1. Single, Double and Multiple entry visas

Sample (click to enlarge)

China issues visas that allow one entry, two or multiple, the last two allowing you to exit from the Chinese mainland and re-enter on the same visa.  You should remember that even a few hours in Hong Kong or Macau is an exit from mainland China in this context.  To return you must either have another valid entry or obtain a new one.  Also, remember that you cannot gain extra entries on a single or double entry visa once it has been issued, you would have to apply for a new one. 

The application form lists the number of entries and total durations that are available, though of course the embassy or consulate can decline to issue a particular type, or indeed, any if they choose to. The maximum stay on a single entry tourist visa is normally 3 months and each entry on a dual or multiple entry one is 2 months. However, you might be permitted less, or if you have relatives in PRC the regulations are often more generous. It seems that the authorities are less willing to issue multiple entries outside of your home nation.  

The fee varies for the more entries and duration of the visa (except for US citizens where the fee is the same – so you might as well 'go for broke'!) For more information, please refer to the Chinese Embassy in Washington DC, USA).  Simply apply for what you want and in the section where you list the places you will visit, indicate your intentions to go to Hong Kong, Macau, Vietnam or wherever, so they see a need for the extra entries.

Tourist Visa applied for outside China, can be for a maximum of 12 months with multiple entries with the final entry date stated on it.  In fact, a multiple entry one with a maximum stay of 2 months per visit allows you as many entries as you like until the final entry date is reached, then you are allowed 2 months as your final period.  So in the above situation you can get up to 14 months.

An often asked question is how long you must be out of China – there is no minimum, you can just go through the controls and turn round and come back in again.

2. Validity (enter before)
Validity shown as "enter before" refers to the time limit of visa. The holders must use the it to enter mainland of PRC before 24:00 on the exact day of expiration, otherwise, it expires after time limit and cannot be extended no matter whether there is number of entry left, and reapplication is required. The validity is 3 months, 6 months, one year and two years. It is suggested to check the validity to assure the visa is good to be used. 

3. Duration of Each Stay (after entering)
Duration of stay refers to the maximum number of days visa holder is permitted to stay in the Mainland of PRC each time, which is counted from the date of entry. If extension of the duration of stay is needed, applicants should apply for a new one at the exit & enter department of local public security authorities before it expires. Overstaying is against the Chinese laws and regulations, punishments such as fines or even expulsion will be made, therefore, it is suggested to check visa to avoid overstaying. 

 Chinese Visa Application Requirements
Application Requirements at Embassy/Consulates of PRC in USA
Application Requirements at Embassy/Consulates of PRC in UK
Application Requirements at Embassy/Consulates of PRC in Canada
Application Requirements at Embassy/Consulates of PRC in Australia