This experiment was conducted to study the effects of dietary supplementation with 25-OH-D3 on the antibody and cytokines in serum and intestinal contents of weanling pigs with or without rotavirus challenge. Forty-eight 28-day-old three-way cross (Duroc×Landrace×Yorkshine) weanling pigs with an average body weight of 7.35 kg were randomly assigned into 4 treatments with 12 replicates and 1 pig in each replicate. The experimental period lasted for 21 d. The pigs of control groups with or without rotavirus challenge (C+ or C-) and experimental groups with or without rotavirus challenge (T+ or T-) were fed diets with 220 and 2 200 IU/kg 25-OH-D3, respectively. The C+ and T+ groups were challenged orally with 1 mL human rotavirus (1×106 TCID50/mL). The results showed that dietary supplementation with 2 200 IU/kg 25-OH-D3 had elevated the level of rotavirus antibody in serum and intestinal contents of pigs with rotavirus challenge at d 5 and 21 (P<0.05), had decreased the serum immunoglobulin G (IgG), immunoglobulin M (IgM) and immunoglobulin A (IgA) contents of pigs without rotavirus challenge at d 5 (P<0.05), and had reduced the serum IgA content at d 5 and 15 (P<0.05) and serum IgM content at d 15 （P<0.01） of pigs with rotavirus challenge. Dietary supplementation with 2 200 IU/kg 25-OH-D3 had a decreasing trend of interleukin-2 (IL-2) and interleukin-6 (IL-6) levels in serum and intestinal contents and interferon-γ (IFN-γ) level in intestinal contents of pigs with or without rotavirus challenge (P>0.05), had enhanced the interleukin-4 (IL-4) level in serum and intestinal contents of pigs without rotavirus challenge (P>0.05), and had increased the serum IL-4 level at d 5 (P<0.01) and IL-4 level in intestinal contents at d 15 (P<0.01) of pigs with rotavirus challenge. These results indicate that dietary supplementation with 2 200 IU/kg 25-OH-D3 can increase the rotavirus antibody level in serum and intestinal contents with or without rotavirus challenge, reduce the secretion of proinflammatory cytokines and the inflammatory responses concerned with them, promote the production of anti-inflammatory cytokines and the anti-inflammatory responses concerned with them, and enhance the ability of disease resistance of weanling pigs.［Chinese Journal of Animal Nutrition，2011，23（1）：34-42］