In greenhouse, eggplant growth and water use efficiency were studied under normal irrigation and fixed irrigation and alternate irrigation. The results showed: in initial stages of growth, plant length of fixed irrigation was the tallest, normal irrigation was the shortest in 3 treatment; leaf area of normal irrigation was the smallest, and alternate irrigation was the biggest in 3 treatment; number of leaf and content of chlorophyll under alternate irrigation was the most, and normal irrigation was the fewest. In procreate metaphase and anaphase, varieties of numbers of leaf and content of chlorophyll of eggplant were similar to initial stages of growth，plant length of normal irrigation was the tallest, plant length of alternate irrigation was the shortest. Photosynthetic rate of alternate irrigation was the highest, fixed irrigation was the lowest in all treatment. The yield of eggplant was the highest by 19.78kg in alternate irrigation. Its increased yield was 19.52% and 25.35% than normal irrigation and fixed irrigation. Water use efficiency of eggplant was 21.98% under alternate irrigation. It’s enhanced water use efficiency were 139.17% and 25.39% than normal irrigation and fixed irrigation.