Abstract: In the present study, the milk performance and optimal variable levels of Yili horse were forecasted by analyzing the correlation among the peak production, early milk traits and whole period milk yield as well as the influence factors of milk protein rate.The correlation coefficients were analyzed by one-way ANOVA and calculated by Box-Behnken Design to explore influence factors on milk quality.The results showed that there were positive correlation between daily peak production, early period milk traits and the whole period milk yield and the correlation coefficients were highly significant ( p < 0.05) . All the early period milk traits were also extremely significant positive correlated ( p < 0.01) . The highest milk protein rate was 2.79%, which occurred during the second to third month of lactation, when the sampling time-point was 14: 00 and the milk production was 8.17kg /d.The results would provide reference basis for early selecting milk horse with high milk yield, breeding specialized milk horse breeds, finding out the balance between milk yield and milk composition.