Abstract: Two Zoysia F₁ segregating populations of the reciprocal crosses of Z136 and Z039 were obtained, and the heredity of the green period in two F₁ populations (Z136×Z039 and Z039×Z136) was analyzed by the major gene and polygene mixed genetic model to show the underlying genetic. The variation in range of green period of both crosses was 178-261 and 188-253 d, well beyond that of either of their two parents (248 and 231 d). The average green period of reciprocal crosses were 223.6 and 216.8 d and the significant differences between the two reciprocal crosses further indicated three were maternal genetic effects for the green period in Zoysia. Second, there was a large difference in the genetic models between the two reciprocal crosses: The effect of maternal genetic and of environment were both significant to the green period. No single major gene model (A-0) was the most suitable for the green period of Z136×Z039, but the green period of the reciprocal cross Z039×Z136 were controlled by two equal additive major genes. The most suitable model is B-4 and the heritability of major genes of the green period of reciprocal crosses was 94.35%.