Travelers should arrive at the airport within the time limit prescribed by airlines, proceed the baggage check-in and boarding pass procedures on time and with the ticket and their valid documents showing identity (ID card or passport). Deadline of domestic flights check-in procedures is 30 minutes before scheduled departure time, deadline of major large-scaled airports is 45 minutes, but deadline of some airports may be one hour or longer. The deadline for international flight check-in procedures is three hours before scheduled departure time. (International flights involve handling of other formalities required by the government). The specific deadline shall to be referred to the statement made on the passenger ticket.
Source: Civil Aviation Administration of China (中国民航总局)