Abstract: In the experiment, two groups of fish w ith an initial body weight of ( 35194 ? 1186) g were reared fed w ith two diets, which contain 30% glucose or corn starch for nine weeks. The results showed that the fish fed with glucose diet had significantly ( P< 0105) higher relative growth rate, feed efficiency and protein ef ficiency ratio than those fed w ith corn starch diet. In addition, significant dif ference was found in the content of mesentery fat between grass carp fed w ith glucose diet and those fed w ith corn starch diet ( 1185% ? 0146% and 3156% ? 0145%) . The results suggest that glucose in the diet has better effects on the growth of grass carp than corn starch in the diet , while corn starch w ill increase fat deposition in the mesentery of grass carp more easily than gluco se.