You used to be able, but not anymore.  At least that is the way it is in the cities I have purchased tickets in (Dalian, Wuhan, Guangzhou, Shanghai, etc...)

In a word, no. In an attempt to eliminate ticket scalping, especially during the Spring Festival travel period, the government introduced a real name registration policy for buying train tickets last summer. It was originally only applied to the faster trains(G, D, etc.), but I believe now applies to all trains.

I have done it on three occasions going between Daqing to Harbin and another time I got a friend to get the ticket while the ticket girl asked if I had my passport. I wasn't carrying it at that time.

Maybe things are a little lax up here. I have heard of the stricter rules however.

In Jinhua, I was able to get a ticket because I forgot to bring my passport with me into the city. But it was more difficult to get into the train station because she wasn't traveling with me. It may be possible, but I don't recommend it.

if you have a student id it will work too

last year i bought Guangzhou to Beijing train ticket and never showed passport,,,good way is to buy from agent they dont ask for passport..

not anymore.but in the university where i'm studying there is an agent that does not require the passport

Yes you can- you need to buy it from the train agency which sells the ticket 10 days before, its probably not procedure but will do it for you you have to pay maybe 5 quai extra fee but all you do is give them a passport or id number so they can put on  the ticket.  This is probably easier if you have a Chinese trans later friend who can say you forgot to take your passport with you.  I have done this twice this summer in Yinchuan, Beijing and friend lost his passport in Guangzhou and did the same.

if you have a student card, then it;s possible, but if not I may tell you that only if you are very lucky,then u can get one without passport ( not recommended)