Abstract: In order to investigate the effects of Xuzhou strain of a Novel goose parvovirus（NGPV XZ-01 strain） on the growth and development of mule ducks, in the experiment, 180 healthy non-immunized mule ducks were randomly divided into three groups, namely the control group, the 3-day-old challenge group and the 7-day-old challenge group, and each group had 60 animals. In the control group, 0.2 mL of sterilized saline was injected subcutaneously at 3 days of age; in the 3-day-old challenge group and 7-day-old challenge group, 0.2 mL of virus solution of NGPV XZ-01 strain(7th generation, titer 5.7 lgELD₅₀/mL) was injected subcutaneously at 3 days of age and 7 days of age, respectively. After challenge, the growth and development, clinical symptoms, morbidity and mortality of each group were observed and recorded; beak length and body weight were measured; all ducks were killed at 25 days of age and subjected to autopsy, pathologic section observation and X-ray examination. The results showed that the 3-day-old and 7-day-old challenge groups were stunted or became stiff ducks after challenge; at 24 days of age, the body sizes of the 3-day-old and 7-day-old challenge groups were significantly smaller than that of the control group, and the body size of the 3-day-old group was significantly smaller than that of the 7-day-old challenge group. During the test period, the 3-day-old and 7-day-old challenge groups showed depressed spirit, lying, piling up, and white or yellowish-white feces; some ducks showed symptoms such as movement disorders and paralysis. With the increase of age, the symptoms of short upper and lower beak and exposed tongue became obvious. The morbidity rate was 90.0% and mortality rate was 11.7% in the 3-day-old challenge group, 76.7% and 6.7% each in the 7-day-old challenge group, and there was no morbidity and mortality in the control group. From 10 to 22 days of age, the body weight and beak length of the 3-day-old challenge group and the 7-day-old challenge group were significantly lower than those of the control group（P＜0.05）; the body weight and beak length of the 3-day-old challenge group were significantly lower than those of the 7-day-old challenge group（P＜0.05）. Anatomial examination showed that the cloaca was enlarged; the intestinal contents were thin, and the liver was edematous and brittle in both the 3-day-old and 7-day-old challenge groups. Pathological section observation showed that the duodenal villi were necrotic at the tip of the epithelial cells; the duodenal villi were detached to different degrees; part of the intestinal glands were necrotic; part of the hepatocytes were necrotic, and the hepatic sinusoids were bruised, with inflammatory cell infiltration; other organs did not have any obvious lesions in the 3-day-old and 7-day-old challenge groups; the control group showed no obvious abnormality. X-ray examination showed that the lower beak, wings, legs and other parts of the 3-day-old challenge group and the 7-day-old challenge group were significantly smaller than those of the control group, and the length of the tibia was much lower than that of the control group. The results suggested that the NGPV XZ-01 strain could cause significant growth and development disruption in mule ducks and was highly pathogenic; and its effect on mule ducks decreased with the increase of the age of infection.