You could be applying for a visa either in your own country, within China or in a third country. If you have any doubts about your situation you should enquire at a Chinese Consulate that issues visas or at a Public Security Bureau Entry and Exit Administration office in China. China does not accept any postal or couriered applications from individuals.
China Visa Application in China (Renewals and Extensions)
It is not possible to renew or extend a visa or change a visa type. However, if you want to spend more time in China, want a multiple entry, or need to have a different visa type, you can - in many circumstances – apply within China. The procedure is very similar to applying outside China, but you must go to the Public Security Bureau (PSM) Exit and Entry Administration office for the municipality where you will be 'resident' on the night following the submission of the application. Smaller centers might not have good English speakers so it is a good idea to take a Chinese friend with you if you can. Ask at international hotels if you are not sure where the PSB Exit and Entry Administration office is.
China Visa Application in China (Renewals and Extensions)
It is not possible to renew or extend a visa or change a visa type. However, if you want to spend more time in China, want a multiple entry, or need to have a different visa type, you can - in many circumstances – apply within China. The procedure is very similar to applying outside China, but you must go to the Public Security Bureau (PSM) Exit and Entry Administration office for the municipality where you will be 'resident' on the night following the submission of the application. Smaller centers might not have good English speakers so it is a good idea to take a Chinese friend with you if you can. Ask at international hotels if you are not sure where the PSB Exit and Entry Administration office is.
The new visa runs from the date of issue (a small difference compared with visas issued outside China which do not start until you enter China) and the old visa is cancelled at that time. So, you cannot have two concurrent visas such as a student and work visa. It is a good idea not to apply until the old visa is about to expire as you lose any unused time on the old one. Do not be concerned that you may have a gap between visas while the new visa is being processed – if you apply just before a week long closure of the PSB office such as Spring Festival, you might get up to 10 days 'for free'!
Always make sure you apply by the last day of validity of the old one, earlier, if the expiry is on a non-working day, and that you have all the required documentation. If you are late applying, you have overstayed your visa and are subject to a fine and possible expulsion.
If you run into difficulties when at the PSB, it is a waste of time getting irate or trying to bluster your way through, it simply doesn't work. Stay cool and you will generally find the officials help and explain all they can.
Currently, it seems that one month is the standard period for regular tourist visas issued in China. Longer ones are available in some situations such as for persons married to Chinese nationals.
Complete the application form from the PSB Exit and Entry Administration office for the locality where you are registered as residing the night of the application, (ie AFTER you apply). It is probably easiest to take the application in yourself. If you have a friend submit your application there are additional regulations.
The section what you must submit for a visa application explains what you need to get together before you apply. One point is that you must include 'photocopies of your passport id page, your current visa, and your last entry stamp; and a residency registration'. The residency registration comes from the regulation that all foreigners must register their accommodation details within 24 hours of arriving (48 hours in remote areas) – as explained below.
If you are staying in a hotel certified to accommodate foreigners - this excludes most budget hotels, but youth hostels affiliated to the Chinese YHA are ok – they can provide you with a hotel accommodation registration slip, (旅馆住宿登记 lü guan zhu su deng ji) for the night of the date you are making the application, not the one before! If you are not staying in a hotel, you must obtain an accommodation registration printout from the police station for the area you are living - and where you should already have registered. So if you are staying in a non accredited hotel or with friends or in an apartment but have not registered, you should either register or stay in an accredited hotel for one night in order to get the slip.