Pearls are known as “the queen of gems”.The improvement of the cultured pearls quality is the focus of pearl industry and the important topic in the research field of pearls.In this paper we summarized the standard of evaluating the quality of cultured pearls in six aspects,including color,size,shape,lustre,surface finish and nacre thickness of nucleated pearls.The major species of pearl oysters and mussels were introduced as well as the characteristics of freshwater pearls and nucleated seawater pearls they produced.The relation between the sizes,the shell colors of the pearl oysters and mussels and the pearl quality was discussed.In this paper,we emphatically introduced the influences of the species,ages and shell colors of donors oysters and mussels,which were used to prepare mantle transplantation(allograft),on the pearl quality.And the influences of the chemicals factors,the means of separating mantle transplantation(allograft)and the number of the mantle transplantations during the implantation of mantle transplantation on the pearl quality are also introduced.How the culture conditions influenced the pearl quality was discussed in addition,and the culture conditions included water quality and microelements,water depth,culture pattern and period to culture the pearl oysters and mussels.