Two 8-week feeding trials were conducted to investigate effects of different rapeseed meal levels（0.0 - 50.0% ） on growth, feed utilization, blood biochemical indices and toxins residues in grass carp（ Ctenoparyngodon ideUus ） （ average body weight were about 5.0 g and 18.7 g）. The results showed that： with the increasing of the rapeseed meal levels, the weight gain rate, specific growth rate,feed efficiency ratio and protein efficiency ratio decreased, but no significant difference was observed in 0.0, 10.0% ,20.0% and 30.0% groups. Glucosinolate（ GLS ）, isothiocyanate （ITC） and oxazolidine thione（OZT） content in the muscle and liver also increased with the rapeseed meal level increasing in average body weight 5.0 g; In average body weight 18.7 g, there were no significant difference in serum glutamic-oxalacetic transaminase, glutamic-pyruvic transaminase, glutamic-oxalacetic transaminase/ glutamic-pyruvic transaminase, total protein, albumin, globin, albumin/globin, urea nitrogen, glucose, creatinine, T3 and T3/T4 , but T4 and T3 ＋ T4 levels were significantly lower than those of control, liver cells were damaged. From the two trials , a percentage of no more than 30.0 % of rapeseed meal supplementation in the feed was suitable.