The objective of the present study was to evaluate the effects of feeding broad bean on haematology indexes and redox balance of grass carp (Ctenopharyngodon idellus). Grass carp with body weight of (936.7±6.1)g were fed formula feed (control group) and broad bean (broad bean group), and then were sampled for measuring haematological indexes and redox balance indexes at various time points. Results showed that the amounts of white blood cells and lymphocyte, hemoglobin level, average corpuscular volume and average corpuscular hemoglobin are affected by both diets and feeding period. At the 12^th week, fish fed broad bean had a significantly lower amounts of white blood cells, lymphocytes, red blood cells and lower hemoglobin level than control fish (P<0.05). The hepatopancreas CAT activity at the 4^th week, the gills superoxide dismutase (SOD) activity and the muscle malondialdehyde (MDA) content at the 8^th week, the hepatopancreas SOD activity, the SOD, catalase(CAT) activities of muscle and gills and the MDA contents in hepatopancreas and muscle at the 12^th week, were all significantly increased by feeding broad bean (P<0.05), when compared with control group. In terms of tissue glutathione level, fish fed broad bean had lower level of reduced glutathione (GSH) and lower ratio of GSH/GSSG (oxidized glutathione) in gills and muscle at the 4^th week, lower GSH level, lower ratios of GSH/GSSG in hepatopancreas and gills, and lower GSH/GSSG ratio in muscle at the 8^th week than those of control group (P<0.05). At the 12^th week, the GSH level and ratios of GSH/GSSG in gills of fish fed broad bean were also significantly lower than those of control group (P<0.05). In conclusion, feeding broad bean could produce cumulative damage to haematological indexes and redox balance of grass carp, and some measures should be taken to promote the anti-oxidation property of the fish.