Abstract: In order to study the growth and development of Oula sheep, newborn Oula sheep（163 rams and 27 ewes） with similar body weight were selected as the research objects, and their body weight was measured at newborn, 8, 18, 30 and 36 months of age. Three nonlinear regression models（Logistic, Gompertz and Von Bertalanffy） were used to fit the growth curve of Oula sheep, and the three models were used to estimate the body weight, inflection point age, inflection point weight, maximum monthly increase, relative growth rate and absolute growth rate of Oula sheep at 8, 18, 30, 36 months of age. The measured body weight and average daily gain, model estimation and measured value of male and female Oula sheeps were compared and analyzed, and the cumulative growth curve, relative growth curve and absolute growth curve were constructed. The results showed that the growth curves of male and female Oula sheep were well fitted by the three models（R~2＞0.960）, and the fitting degree of the three models was almost the same. The inflexion point age of male sheep was later than that of female sheep, and the inflexion point weight was higher than that of female sheep. The relative growth rate and absolute growth rate of rams showed a downward trend, and their early growth intensity was greater than that of the later period. The estimated weight of ram fitted by Logistic model was closer to the measured value, which was the best model for the growth curve of ram. The expression of the model was Y（t）=84.279/1+7.145×exp（-0.215t）. The estimated weight of ewes fitted by Von Bertalanffy model was closer to the measured value, which was the best model of ewes growth curve, and the model expression was Y（t）=70.295 ×1-0.483×exp（-0.118t）~3. The results indicated that the Logistic model was more suitable for the growth of Oula rams, and the Von Bertalanffy model was more suitable for the growth of Oula ewes.