Abstract: The main aim of the present study was to assess whether the genetic parameters on the egg production in Rugao Yellow Chicken changed with different models. The production recorders on the Rugao Yellow Chicken were collected from 2009 to 2012. Animals included 8575 individual fowls from 242 sires and 1362 dams. The evaluated models were consisted of uni- and multiple-trait model. (Co) variance components were estimated with AIREML method using WOMBAT software. Results suggested: (1) the day at the 1st egg should be included in the fix effects because of its important role in early egg production; (2) since the direct genetic covariance was less than that of permanent environment, it seemed safe to conclude that the environment was the main phenotypic variations sources; (3) the heritability of egg numbers was high at the early laying period, low at the peak of the laying phase, and increased again at the late laying period; (4) for Rugao Yellow Chicken, the genetic correlations between the monthly egg production and EN40 ranged from 0.67 to 0.79, the correlations of neighbor months was high; (5) considering the correlation between early and terminal laying phase was low, it was necessary to increase statistical times during local fowl improvement.