First, allow me to explain a small technical detail to you, and I do not know if you are aware of it or not.  Actually, your "Z" work visa is technically no good 30 days after you enter China.  This is so because within those 30 days, you are supposed to go (and prior to start working) to the local PSB and obtaing your Health Certificate, your FEC (if not done already), your work permit and your residence permit.

Now, since your work and residence permits are cross referenced to your passport number, if you loose your passport technically they are not longer valid.  And this is the reason that you will need to request a new one.

So, what will you need to do ?.  First, go to local Police nearer where you live and report that your passport was loss/stolen, and get from them a document stating that you reported so with a case number on it.  With that, the next two things are to go to your country Embassy or Consulate and request a new one, and second to go to PSB office with document from local Police and request a 30 day permit to stay in China while you adquire a new passport.  Once your new passport arrives, go with it to local PSB and see if they will issue a new working and residence permit with the new passport number on it.  Sometimes they do, sometimes they will give you a permit to exit China and then you must leave and request a new working visa abroad and return to China and go thru the same procedure with health, etc.

Not as difficult as what HappyExpat said if you have at least a copy of  your current Resident Visa and your face page. The problem lays in the laziness of the PSB people. If you just go to them and say I lost my passport but have no copy of your visa, they will send you on your way. But you are able to force them to look up your name and visa number because all foreigners are registered on line when the Resident visa is done. This is something I have dealt with many times and usually end up in a shouting match with an officer who really isn't that busy but acts like it will kill him to touch a few keys away from his QQ page.

That being said, if you are employeed let your company foreign administration handle it, if not you have to be sweet and sour to the PSB. I have yet to see anyone who has had a lost or stolen passport have to exit after getting a new passport. Or renew a health check and so on

I deal with about 50 of these every week. Keep your passports safe please.

For one split second, I thought "Ryan" was back...

HappyExpat, that's also why I said I handle about 50 a week, it all depends on the way you handle it. If you go empty handed expect more trouble, if you go on a relatively busy day, it is difficult. Also what I stated let your employer do it. More than one thing can happen in a different situation.

Carry a small money card,, put 500rmb on it and hand it in along with your documents. Or find someone like me and pay me for the trouble, or find someone who knows someone and have them politely ask the official to a nice dinner and take your paperwork with you.

I think sometimes you're a little over critical because you have dealt with some difficult situations and I understand that. So if you need any advice on how to cut down on your company taxes, liquor tax and sales, invoice collection, accounting problems, importing tax and so on, let me know, I deal with this everyday for foreign run restaurants and bars. Along with other legalities that keep me busy.

And HappyExpat, sorry to hear about that about your daughter, what rubbish, was she on your FEC? If not she should be, any visa should represent the visa that you have. Is she still with you?