This experiment was conducted to study the histopathological change of phosphorus deficiency in juvenile Jian carp (Cyprinus carpio var. Jian). Three hundred juvenile Jian carp with average body weight of (7.17±0.01) g were randomly divided into 2 groups with 3 replicates each and 50 juvenile Jian carp in each replicate, and were fed with diets containing 0.17% (deficiency group) and 0.55% (control group) phosphorus, respectively. The experiment lasted for 63 days. The results showed as follows: phosphorus deficiency resulted in putrescence and exfoliation of intestinal epithelium cell; denaturalization, dissolution and putrescence of vacuole in hepatocyte; putrescence and disintegration of pancreatic gland alveolus; disruption and exfoliation of pronephros cell; disruption and putrescence of metanephros renal tubular; cell disruption and vacuole denaturalization of spleen; dissolution and fracture of heart muscle fiber; putrescence and exfoliation of epithelium and disappearance of cartilage in gill flake; and disintegration and putrescence of muscle fiber. These results indicate that different histopathological injuries in tissues and organs are caused by phosphorus deficiency in juvenile Jian carp. ［Chinese Journal of Animal Nutrition, 2010，22（5）:1328-1333］