Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 430079, Peoples R China
; China Ctr Adv Sci & Technol, Beijing 100080, Peoples R China
Based on three methods of particle identification(PID) of BES, we study the identification of p and (p) over bar in momentum range from 0.3 to 1.2 GeV using real particle samples of e, mu, pi, K, p and (p) over bar which were collected in 2-5GeV R scan, J/phi and phi' data taking periods. The paper presents the optimized method of PID:p((p) over bar) is identified by dE/dx only if momentum below 0.6GeV,and by TOF or the combination of dE/dx and TOF for higher momentum. The PID efficiency of p,(p) over bar and contamination from the other charged particles are also given.