Abstract: 【 Objective 】 The purpose of this article is to understand the relationship of muscle fiber characteristics with meat quality and its breed and sex differences in pigs by collecting and analyzing the relative references. 【 Result 】①The formation of muscle fibers is a very complex biological process. The number, size and type of muscle fibers are the basic characteristics of muscle fibers. ②At present, the most commonly used classification method of muscle fibers is based on the polymorphic expression of MyHC gene in muscle fibers. ③Before birth, MyHC isomers were expressed in the order of embryonic, fetal and mature stages . After birth, the muscle fiber types were transformed into each other. ④Different types of muscle fibers can influence muscle color, pH, water hold capacity and so on because of their different metabolic characteristics. The size and density of muscle fiber also affect muscle quality because they are closely related to the type of muscle fiber. ⑤Different breeds of pigs show different muscle quality because of their different muscle fiber characteristics. The characteristics of muscle fibers are different between the sexes in order to adapt to their own growth and physiological needs.【 Conclusion 】The characteristics of muscle fiber in pigs directly affect the meat quality. Because of the various breeds and sexes, the formation of muscle fiber characteristics is different, which shows muscle quality is different.