Abstract: To investigate the loss mechanics of piezoelectric ceramic materials,Pb_0.9Ba_0.05 Sr_0.05（Sn_1/3Nb_2/3）0.06（Zn_1/3Nb_2/3）0.06Ti_0.44Zr_0.44O₃ was studied by changing its forming technique and by doping with Co₂O₃ and Sb₂O₃,Mn（NO₃）2 and Sb₂O₃,respectively.Under the same sintering condition,the ratio of mechanical loss and electric loss was 0.09,when the specimen was doped in Mn（NO₃）2 together with Sb₂O₃,the ratio was about 0.55 when the specimen was doped in Mn（NO₃）2 together with Sb₂O₃.The experiment results show that there is a good correlation between the mechanical and electric losses for the PBSZT piezoelectric ceramics,while the similar composition.The forming experiment results show that the different forming affects the ratio of the two losses obviously.