Based on a seedling growth experiment in cucumber cultivars "Zhongnong203' and "Chiyu401' under different temperatures in growth cabin, growth analysis of seedling and establishment of CUSSIM (cucumber seedling simulator) model in cucumber were investigated. The results indicated that total dry plant weight, plant height and leave number of cucumber seedling were significantly decreased by temperature reduction.; there was significant difference in growth rate and total dry plant weight between different cultivars; the functional relations those natural logarithm of total dry plant weight of cucumber seedling (LnDW) and relative growth rate (RGR) against days of seedling growth (t) at different stages for each treatment could be simulated by a quadratic function and liner function, respectively. Based on above results and some experiential parameters in practice of cucumber production, the CUSSIM model of cucumber seedling was established with Powersim software.