Abstract: The objective of this experiment was to study the effect of application of selenate and selenite to soil on the fruit quality of tomato. Two different varieties of tomato were employed as the testing materials. Selenate and selenite were applied to the soil with various concentrations (0, 7.5, 15, 22.5 g/hm²), and then five basic quality indicators of ripe tomato fruits were measured. The results showed as follows: the concentration of soluble solids, vitamin C, soluble sugar, sugar acid ratio and soluble protein in test group, which was treated by Se-fertilizer, was higher than that of the control group. With the increasing concentration of Se, an approximate trend of all five indicators, which has increased first and then decreased, has been observed. This suggested that the effect of selenate was better than the effect of selenite and the first species (the tomato of large size) was better than the second (the tomato of small size). The results indicated that the best treatment for the first species of tomato and the second species of tomato was selenate with 15 g/hm² and selenite with 7.5 g/hm², respectively.