Abstract: To assess the impact of fertilization on mineral element content in the forage and in blood of grazing Guizhou semi-fine sheep, fertilization and grazing experiments were conducted in the Liangshuiguo pasture area of Weining county. The average concentrations of N in the forages from the fertilized pastures were significantly higher than in those from the control but there were no significant differences between the fertilized pastures. The average concentrations of S, Mn and Zn in forages from the pastures fertilized with ammonium sulfate were significantly higher than those treated with other fertilizers. The application of ammonium sulfate led to a significant reduction in selenium content of the forages. At the end of the study period, the Cu, Fe and Se contents in the blood of Guizhou semi-fine sheep from pastures fertilized with ammonium sulfate were significantly lower than in those fertilized with ammonium nitrate and from the control while the Mn, Zn and S contents were significantly higher. The blood hemoglobin (Hb), packed cell volume (PCV) and serum ceruloplasmin (Cp) contents and the activities of serum SOD, glutathione peroxidase (GSH-PX) and CAT of Guizhou semi-fine sheep from the pastures fertilized with ammonium sulfate were significantly lower than in those fertilized with ammonium nitrate and from the control. Thus, Liangshuiguo pasture area should not be fertilized with ammonium sulfate.