I will tend to say "NO", they normally do not go knocking on doors to check papers.  But they do catch you when you do need some service and go to see them, or at your place of employment.  At work yes, they do go and check once in a while that all foreigners are complying with all requirements, like visa, work permits, temporary residence permit, valid residence permit, etc.

That is my experience in Guangxi Province, in other areas could be different.

Yeah, I heard they do. I was here for a stint during the Olympics, and many friends got knocks on the door because they failed to register at the police station within 24 hours. They were made write an apoogy letter and got off with a warning, but I heard that not everyone was so lucky.

Another friend had an expired visa and was tracked down and given a warning. They seem to scare people first before taking severe action, but you'd be foolish to underestimate what they could do to you.

This all depends upon the area of the country, the size of the city where the foreigner is living, etc., etc.

In the city where I live a Canadian was thrown in jail, actually thrown in jail, where he sat for a long period of time for having overstayed his visa but then again, he had overstayed the visa by nearly three (3) years.  Incredible story but a very true one.

Consequentially, in the city where I live, foreigners are apt to receive visits at home from the local PSB perhaps 1 - 2 times in year, if that, but they do actually occur and they occur in the evenings on top if it, between 21h00 - 22h00.

yes they do and they are not joking either, they will come to your door with their guns pulled in groups of 6, keep all your papers handy.

I got the knock and they pushed themselves in the door and took a quick visual of the whole apartment then they ask me for my papers, I show my FEC, and my passport and they still wanted to see more so i had to show them my marriage certificate and my daughter passport as well and my wifes.

Only after they saw all those papers did they put the guns away and then walked out.

I later found out that one of my neighbors called them and told them I was here illegally. So the lesson here is make friends with your neighbors, this neighbor I never even met they just saw me using my key one time and called the cops. Stupid xinophobic idiot.

Yes

and will be more often in the future, I think they aware of many illegal living people nowadays.

NO

The police 'will not' knock on your door if you have an irregular or expired visa. They will however catch you at the airport once you show them your visa is expired or irregular and that's where all the trouble begins for you. You'd have better luck at those guys that place the call girls card up on your door to knock on your door and they are as quiet as a mouse. 

Sorry Mattaya but your answer is blatantly incorrect.  The Exit-and-Entry folk at the PSB relay the visa information to the local neighbourhood police.  They are the ones who will show up at the door.  And they do show up in mid-sized to larger provincial cities.  In Shanghai, Beijing, Guangzhou, it's just logistics as there are too many foreigners but there are random ways in which one can be snagged -- traffic accident, random ID checks at night as happens, someone reports, etc., etc.  Of course they will find it out at the airport but they will learn of it long, long before then.

The PSB are highly, highly computerized in terms of foreigners these days.  Ten years ago, each province had its own computer system.  These days they are integrated nationally.

This is just the very, very wrong country in which to overstay a visa or mess around with the PSB. 

I can speak from personal experience that cops will come to your door to solicit bribes when they figure out that you are a foreigner living in a building that's unauthorized to rent to foreigners.

They absolutely do, yes. One of my friends who was working on a L visa one night had police at his door. I don't know how they found out, but he was deported. I think they gave him a week, possibly two, to get out of the country.

YEs they do. They came knocking on my door at 10 :00 pm two years ago because they thought I had not registered at the local PSB station. Fortunately my paperwork was all in order.

Only if they want a bribe. I had them come to a hotel in my wife's hometown on a visit, didn't take my passport, they wanted 1,000rmb. I got out my laptop and logged into the PSB website and showed them my visa number and picture. As funny as it was they didn't even know how to do it themselves, I still treated them to a dinner and a beer while laughing about the situation

I'm not sure about gun tooting police, however I have had them knock on the door and take my passport away for clearance. I've lived in Zhangjiagang for 4 years + and the local station administrator is quite strict, each time I leave to visit the UK or Hong Kong, and each time I return again, she will phone my home to remind me to re-register. And usually about 7-10 days before my visa is due to expire she will also phone to remind me to pack my bags or renew. This I do not mind however she could do it more politely not with the attitude or authoritive manner .

   Yes they do.    I have had them show up at our apartments at least one to two times a year.   They always wanted to see my passport .   I have even had them ask for my idea out in the street at night.    They will randomly check the passengers on buses.   Will they come out in mobs and drobes to go looking for all foreingers?   NO.  Why because that would cost them a lot of time, money, and resources.    However, I do believe they may ask people who live in buildings, hey have you seen any foreingers in this neighborhood?   Than they probally check them.  I have been very lucky they have never asked me for any bribes.      Yes, they will check schools.  

i have never had the police knock on my door and ive been to china 9 times just usually for 6 to 8 weeks twice for a year but never have been bothered

they come to my house 3 times in 3 years

They never came to visit me in Hunan, ever. In fact, I saw cops doing a visa check in Guangzhou, and they just let me walk past.

Heck, they even waved to me... I was wearing a suit, and the others were black dudes in poor clothes (my suit was less than 250 RMB, but it sure looks good!). Might be my white skin? I actually feel kind of bad about it.

I also regularly wear a suit when outdoors. I only once got stopped by police, and that was last year in Guangzhou during Canton Fair season. When asked what I did, I explain in Chinese that I was a Medical-Scientist traveling from Hong Kong University to SYS University (ZhongDa).. After which time they sent me on my way. No fuss.

Frankly speaking, the Chinese are hard pressed to get western foreign nationals with at least one Ph.D. in science or medicine to reside here. If I flash one of my lab badges, most leave me alone. In ever other situation, I have never been bothered by any government organization. So, I suppose problems with them also depends on your chosen profession.