Based on investigating 195 pig-raising farmers in Guanzhong area of Shaanxi province,this paper made an positive analysis on scale change efficiency of pig-raising farmers and its influencing factors by using Logistic binary choice model.The result shows that several internal factors have significant impact on scale changes efficiency of pig-raising farmers which include the age,education,raising scale,the number of pig-raising labor,net income from pig raising etc.At the same time,some external environmental factors,such as farmer’s participating in pig-raising cooperatives,the Government’s providing services and training to pig-raising farmers also have significant impact on pig-raising scale changes efficiency.Finally,in order to make a healthy and orderly development for China’s pig industry,this paper put forword some suggestions that the Government should have long-term planning for pig industry,perfect the policy of providing subsidies and insurance for pig-raising farmers,provide preferential loans to farmers,strongly support the development of rural pig-raising cooperatives and advocate raising pigs with moderate scale.