Visiting china for Bauma fair in November this year

You can apply for a tourist L types to attend the Bauma fair.
You should first prepare the relevant documents: passport and its copy, a filled-out application form, a passport-style photo, round trip air tickets and hotel reservation. Besides, Sri Lanka passport holders also need to provide a letter from a local travel agency, an invitation letter from Chinese tourism bureau, travel itinerary and recent bank statement.
Next, submit the application to the embassy of PRC to apply for the L types.

Dear Sir
thank you for your reply,
regarding sri lankan (two persons) we work here in Japan,we have working visas. our company sponsors us. and also our Chinese suppliers reserve hotels for us. our suppliers also send us invitation and we also have registered on line as visitors for the fair. do we still needs a letter from Chinese tourism bureau and Japanese travel agency and prove our bank accounts?
please let us know.
thank you