Abstract:Abstract : Research purposes : On the basis of analysis of the anti - overturning stability of end wall portal structure, integral method for calculating the anti - overturning of end wall portal structure system has been put forward. The research results can be a reference in theory and method for the design and code revising of railway tunnel portal. Research conclusions: Through this article research,such conclusions can be acquired: ( 1 ) The integral method considers the favorable effect that lining has a steady fixation effect on tunnel portal. The integral method is simple in computation, high in reliability and convenient for application. (2) The results show that resistive overturning safety factor is increased by 17.2% and the location of the applied points of resultant earth pressures raises 0. 92 m when using the integral method. Compared with the traditional calculation method, the integral method is more reliable, economical and reasonable. (3) The integral method is recommended in tunnel portal stability evaluation and design. Anti - overturning stability of all kinds of railway tunnel portal structure yet have not been studied, there are many issues need further study and discussion.