Sequencerelated amplified polymorphism (SRAP) markers were used to examine the genetic variation of three consecutive generations (F₁, F₂ and F₃) and one backcross generation (BC₁) in pearl oyster Pinctada martensi family with redcolor shell. A total of 63 bands were generated with 7 primer pairs, among which 55 were polymorphic bands. On average, 7.86 polymorphic loci were generated with each primer pair. The Shannon information index and the Nei’s gene diversity indexes in the F₁, F₂ and F₃ showed a reduction in genetic diversity, with no significant difference in genetic diversity among generations (P>0.05). With the increasing of generations, the differentiation between contiguous generations showed a inclination of reduction, but genetic identity within generation increased. The genetic similarity between BC₁ and F₁ was higher than that between F₃ and F₁, and the result showed that offspring inclined to recurrent parent by backcross. The results would provide theoretical guidance to the farming and breeding of pearl oyster.