Abstract: Based on the analyses of the role, functions and passenger flow characteristics of Guangzhou- Zhuhai intercity rapid mass transit, the basic idea that intercity mass transit should be taken as a regional passenger corridorwas proposed, and the technical route of passenger volume forecasting based on the four- step forecasting method was put forward. By applying the combined model for passenger flow assignment, the passenger volume of Guangzhou-Zhuhai rapid mass transit was forecasted, and its daily passenger volume, passenger turnover, average transport distance, and maximum transect volume during rush hours were gained.