The data from the record of 1131 birds of synthetic population (A line) and 1587 birds of selected population (D line) through 3 generations (1977-1980) were used for the estimates of expected genetic gain by selection indices based on the additive effect only and maternal and additive effects. It was found through Hazel`s method considered the only additive effect that in both lines the first egg day and egg weight at 43 weeks of age were decreased while egg number to 43 weeks of age was increased, and body weight at 43 weeks of age was slightly decreased. And A line showed more satisfactory genetic changes compared with D line except body weight. Expected genetic gains in A line based on genetic parameters estimated using additive and maternal genetic effects simultaneously were the most significant for increase of egg number among the four traits studied and egg weight was 2.50g heavier than performance of this generation, while body weight and the first egg day were decreased, which were considered most desirable in genetic changes of layer. In line D genetic gain of egg production could be achieved through maternal genetic effect with maintaining body weight nearly constant. And major profitable egg weight was decreased by 0.87g lower than that of this generation, and the first egg day was also shortened. According to above results genetic improvement using the additive and maternal effects may be achieved more desirable than that using the additive effect only.