You need actual passport of more than six months validity with a blank visa page; One completely-filled application form (The People's Republic of China Visa Application Form) with one recent passport size photo; Bank account statement of applicants (more than 6,000 US Dollars); An official invitation from related Chinese government departments or companies / organizations authorized by Chinese Ministry of Foreign Affairs to issue visa is required. Based on the official invitation with a letter from your company, you can apply for a single, a double entry, or a multiple entry visa.
It takes a minimum of four working days to process a visa. And you can ask for a rush service if you need.