Objective:To investigate the effects of GnRH agonist on the expressions of FSHR proteins in pituitary and ovaries in ewes,also to analyse the bioinformatics characteristics of ovine pituitary FSHR.Methods: Forty-two prepubertal ewes (Ovis aries) were randomly assigned to six groups (n=7).The ewes in experimental group EG-Ⅰ,EG-Ⅱand EG-Ⅲwere subcutaneously injected with 200μg,300μg and 400 μg alarelin antigens twice (at day 0 and 14),respectively.Ewes in EG-Ⅳand EG-Ⅴwere injected sub-cutaneously with 200μg and 300μg alarelin antigen four times (at day 0,7,14 and 21),respectively.Ewes in the control group (CG) were subcutaneously injected with 2.0 ml solvent twice (at day 0 and 14).Fluorescence quantitative RT-PCR was used to detect gene expression of FSHR in pituitary glands.The expression of FSHR protein in the ovaries was detected using Western blot.Results:The 2-ΔΔCt values of GnRHR,FSHR and LHR mRNAs in the pituitary gland of EG were lower than that in control group (CG).The 2-ΔΔCt values in EG-Ⅳ( P<0.05 ) and EG-Ⅴ( P<0.05 ) were lower than those in EG-Ⅰand EG-Ⅱ.Expressions of FSHR proteins in EG ovaries increased.Levels of FSHR proteins in EG-Ⅳand EG-Ⅴ( P<0.05 ) were higher than CG.The length of sheep FSHR sequence of nucleotides were 1 091 bp,the homology of FSHR sequences was 100% with that reported in NCBI.The theory isoelectric point , half-life,unstable index,fat index,hydrophobic average were respectively 1.2 h,5.05,47.75,0.836 and 30.61.Conclusion:Alarelin active immunization can inhibit the expression of FSHR mRNA in the pituitary gland ,but increase FSHR expression in ovarian of ewes.FSHR is an unstable hydrophobic protein.