This study was conducted to estimate genetic parameters of type traits and evaluation of their genetic trends. For this purpose, 16837 records provided by Shir VA Gousht dairy farm Company in Isfahan, Iran were used. Data were obtained from animals born within years 1990 to 2010. Data was analyzed by average information restricted maximum likelihood method (AIREML). Genetic relationships were estimated using multivariate analysis. Genetic trends were obtained through regression of breeding values on birth year. This experiment indicated that the type traits had relatively large changes by age of animal. The results showed genetic relationship of angularity, teat placement and udder depth traits were stronger than other type traits (respectively, 0.68, 0.20, -0.13) with milk production. Strength (0.34) and rear legs rear view (0.31) had a higher genetic correlation with fat percent compared to the other traits while angularity had the highest negative genetic correlation with fat percen (-0.46). Rear legs side view and udder cleft had the highest correlation with lower number of insemination (-0.16, -0.15 respectively) and the rear legs rear view, teat placement, rear udder width and rear udder height had a high correlation with lower dystocia (-0.71, -0.64, -0.51, -0.44 respectively). Udder height and rear legs rear view had a positive correlation with the longevity (0.31, 0.13 respectively), and angularity showed a negative correlation (-0.17) with the lifetime. The genetic trends of type traits determined that teat lengths are becoming shorter. The correlation between milk production and teat length indicated that selection for milk production led to changes in the teat length. Also udder depth scores were increased. Among type traits, in addition to teat length, a high genetic change was observed for stature. It seems stature has increased in the recent years, probably because breeder's regard this trait in the selection programs. Rump angle also had a good improvement, while udder height had slightly decreased. In general, it could be concluded that a good genetic improvement have been occurred during the recent years. Keyword : type traits, genetic trend, Holstein, genetic parameters
