Abstract: Jinan BRT-3 lines which contain different forms of lanes are selected so as to study the operating charac-teristics and the inner relation between constraints and potential factors of bus rapid transit system .The comprehensive approach in this paper can fully describe the working characteristic of the BRT vehicle ,including average speed ,average running speed ,average delay and average operating speed ,as well as 5 basic parameters in intersection delay and 8 high-light operation characteristics as the evaluation index .The operation data in real-time are collected between different sec-tions and stations ,and the key factors affecting BRT are analyzed by using mathematical statistics method and factor anal-ysis of multivariate statistics .The research aims to demonstrate the relationship between operating characteristics and the impact factors ,and to explore methods to improve BRT characteristics .Comprehensive analyses show that the key factors affecting BRT are the intersection impact factor ,the platform dock impact factor ,and the car road comprehensive impact factor .The quantitative analysis has also led to many constructive suggestions .