Abstract: The effects of rice syrup as a substitute for lactose on blood bio-chemical index and hormone level in weanling pigs were studied. A total of 32 weanling barrows (Yorkshire ×Landrace) initially weighing 2.68±0.34 kg and 7d of age were placed in individual cages. Sixteen pigs were randomly assigned to one of two dietary treatments: (1) control, 43% lactose and (2) treatment 1, 0% lactose. Five pigs from each treatment were randomly selected for termination on 14d and 21d, respectively. When the lactose was replaced by the rice syrup, the serum cholesterol was significantly decreased on 14d（p<0.05）, but there was no effect on 21d（p>0.44）. As for the total protein, total triglyceride and insuline, there was no difference between the control and the treatment（p>0.05）. The serum gastrin concentration had no difference between the two groups on 14d（p>0.05）, but it was higher in the control than the treatment on 21d（p<0.05）. The serum T3 level was higher in the control than the treatment on 14d（p<0.05）, but there was no difference between the two groups on 21d（p>0.05）. The serum T4 level was significantly higher in the control than the treatment on 21d（p<0.01）, but there was no difference between the two groups on 14d（p>0.05）.The result suggested that the lactose could stimulate the cholesterol absorption, but had no effect on the protein and fat metabolism, moreover, the stomach might not be the main place for digesting the lactose, the low lactose level and rice syrup could decrease the PH in the pigs’ stomach.