Abstract: BACKGROUND AND AIM To investigate the toxicity in SD rats fed continuously with monascus yellow pigment. MATERIALS AND METHODS SD rats were divided into four groups (0.23、0.47、0.93 g/kg and a blank control) and fed continually for 90 days. During the experimental period， rats were weighed once every week， general conditions were assessed， and feed consumptions were recorded. On the 45th day， blood was collected from tails to perform complete blood count and biochemical tests. After 90 days， eyeballs were extracted and blood was used for blood count and biochemical tests， livers， kidneys， spleens and testicles were weighed， and pathological examinations of livers， kidneys， spleens， stomach intestines， testicles and ovaries were done. RESULTS The body weight increase and feed efficiency of all dose groups were not significantly different from those of control group(P>0.05).Complete blood count the hemoglobin content， erythrocyte count， leukocyte count and differential in all dose groups were normal.Blood chemical test:serum ALT， AST， urea， creatinine， total cholesterol， triglyceride， glucose， total protein and albumin in all dose groups were normal.Organ/body weight ratios the ratios of kidney/body， spleen/body， liver/body， testicle/body of all dose groups were not significantly different from those of control group(P>0.05).Pathological examination:no special pathological changes were found in the livers， kidneys， stomachs and spleens of rats in all dose groups. CONCLUSION No toxic effects were observed in rats continuously fed with monascus yellow pigment for 90 days， suggesting it could be used as a natural pigment in food production.

Key words: monascus yellow pigment, complete blood count, blood biochemical test, body weight, organ/body weight ratio, toxicity