Visa flexibility

Yes,you can change working visa Z ,It depends on your nationality since china only invites English national for teach English.

Thanks for the response. 

Visa status migration is not possible being in china . You need to fly back to your home town and re-apply for a working visa.  The process for working is initiated in your homeland with all. Here post landing its extended for an year. If you want to assure yourself better consult the local embassy in your homeland or the exit entry bureau in china.

In most cases no, one cannot change an F to a Z work visa without leaving the country. Going to Hong Kong (at your own expense) to change one's visa is becoming more and more difficult. Your prospective employer will be able to tell you if you can change your visa in HK or not. Some provinces allow this change, while others do not.

Been there. Done that.

my own recent experience;business visa(M) cannot be changed to work visa inside china anymore. u need to get the necessary documents from your employer and apply for work visa in your country, otherwise you will have to go back again.