Abstract: In order to effectively reduce the growth retardation or stagnation caused by the infection of Eperythrozoon in blue foxes, and the harm caused by the high incidence of "stunted foxes" to the blue fox breeding industry, in the experiment, healthy blue foxes（healthy group） and blue foxes infected Eperythrozoon（diseased group） were selected during the high incidence period of the disease. The effects of Eperythrozoon on the growth and development of blue fox and the digestion and utilization of nutrients were studied by comparing body weight（BW）, BW/DMI, dry matter intake（DMI）, dry matter digestibility（DMD）, crude protein digestibility（CPD）、 crude fat digestibility（EED）,nitrogen deposition rate（NDR） and nitrogen metabolism rate（NMR） of blue foxes in both groups. The results showed that the average BW of the diseased group was only 22.84% of the average BW of the healthy group, which was significantly lower than that of the healthy group（P＜0.01）. DMI and BW/DMI of blue foxes in the diseased group was significantly lower than that in the healthy group（P＜0.01）. DMD、CPD、EED of blue foxes in the diseased group was extremely significantly higher than that of the healthy group（P＜0.01）, and NDR of blue foxes in the sick group was significantly higher than that of the healthy group（P＜0.05）. NMR of blue foxes in the sick group was lower than that of the health group, but the differences were not signifcant（P＞0.05）. The results indicated that the infection of Eperythrozoon was the main cause of "stunted foxes" and development of young fox. The prevention and treatment of Eperythrozoonosis should be strengthened from the growth stage.