Pb (Zr0.95Ti0.05)O3(PZT95/5 for short) anti-ferroelectric nano-powder was prepared by sol-gel method，and the effects of calcinations temperatures on structural stability of perovskite for PZT(95/5) was systematically investigated in this paper. Based on the results of TGA-DSC, calcinations temperature range of dried gel was identified as 550℃ to 750℃. XRD results illustrated that the peak intensity of the main crystalline phase gradually increasing, while that of the impurity phase decreasing, eventually disappeared with the increasing of the calcinations temperature T1. When calcined at 750℃, single phase of perovskite for PZT(95/5) was formed. Observed under SEM, with the increasing of T1, powder synthesized becomes finer and more uniform progressively. And when calcined at 750℃, the average particle size of PZT(95/5) nan-powder is about 100 nm.