Liaoning Univ, Dept Phys, Shenyang 110036, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
A multi-variable particle identification method is developed for the BES II physics analysis. Besides the traditionally used TOF-T and dE/dx information, TOF-Q and BSC-E are also used to improve the particle discrimination ability. It is shown that the particle identification efficiency, misidentification probability and systematic error could be improved with this new method. The multi-variable method can be extended to even more variables, and can be used in other experiments.