Since the soil temperature in closed greenhouses is relatively constant and less influenced by external environment, the ditch cultivation method in closed greenhouses is adopted to conduct tests in this research. Moreover, water is supplied according to the transpiration to create suitable conditions for crops. The differences among the environmental factors of different ditches with various depth and their influences on transpiration rate, yield of Chinese cabbage as well as water productivity are researched. The results show that in high temperature condition the temperature values in 0.7m and 0.9m (the depth of the ditch) are reduced obviously compared with CKi (Check treatment in greenhouse), and the maximum temperature difference is larger than 20℃. The humidity is maintained between 25% and 75%, which is suitable for the growth of crops. The water productivity for each treatment are: 0.9m＞0.7m＞0.5.m＞0.25m＞CKi＞CKo. In high temperature, ditches with the depths of 0.7m and 0.9m are more suitable for the growth of Chinese cabbage. Therefore, ditch cultivation method can solve the high temperature and high humidity problems of closed greenhouse. Meanwhile, it can improve the crop water productivity.