Traning in China, do I have to provide the police clearance?

Brother I am Rashid Mahmood from Pakistan , working as sales manager in a Chinese firm Muyang Holdings ,Jiangsu , my firm has sent me invitation letter and all relevant documents a local travel agent asked me to have police clearance certificate , because I am running short of time its 7 and I have to be there by 17 can you please confirm if it is so necessary you know the police structure in Pakistan , if you can mail your answer to me I shall really be obliged
Rashid Mahmood
Sales Manager
Muyang Holdings , Jiangsu