Improving productivity is the key word for realizing economic growth and development, and labor productivity has a direct relationship with the quality and standards of living. Human capital as a production input affects the labor quality, as a production input, and increases his knowledge and skills. So, improving human capital is expected to improve productivity. Obviously, such a role is of particular importance due to the severe limitation of resources in Iran's agricultural sector. This study investigated the impact of human capital on labor productivity in Iran’s agricultural sector in 1967-2017, using the autoregression distributed lag model (ARDL). The results showed that labor productivity in the short run is positively and significantly affected by a lag of dependent variable, physical capital with two lags, human capital, knowledge and technology, and natural resources. The impact of human capital in the long run is also accepted. So a one percent increase in the human capital index causes the labor productivity in the agricultural sector to increase by 0.82 percent, equivalent to 279.6 thousand rials. The impact of other independent variables, including physical capital, knowledge and technology, and natural resources, on labor productivity in the agricultural sector was evaluated as positive and significant. Also, the effect of dummy variables of revolution and war, and drought on labor productivity was evaluated to be negative. In general, due to the increasing limitation in access to physical and natural inputs, investing in human capital is a high priority in achieving economic growth goals