This study was performed to the expressions of pregnancy-associated plasma protein-A (PAPP-A) and 20alpha-hydroxysteroid dehydrogenase ($20{alpha}$-HSD) in bovine corpus luteum during early pregnancy. To determine the function of PAPP-A gene during early pregnancy, we collected corpus luteum samples on 30, 60 and 90 days of pregnancy in bovine. The mRNA expression of PAPP-A, $20{alpha}$-HSD, progesterone-receptor (PR) and insulin-like growth factor binding protein4 (IGFBP4) gene was conducted by Real-time PCR. In parallel with mRNA levels, The protein expressions of PAPP-A and $20{alpha}$-HSD were detected by immunological analysis. The mRNA expressions $20{alpha}$-HSD and PAPP-A significantly increased on day 90 in the corpus luteum during pregnancy. The mRNA expression of PR and JGFBP4 in the corpus luteum progressively was enhanced at 30 to 60 day, but decreased on 90 day of pregnancy in the corpus luteum. The expression patterns of these genes, PAPP-A and $20{alpha}$-HSD were similar pattern in these tissues. In conclusion, PAPP-A and $20{alpha}$-HSD activity in corpus luteum could be played a role for early pregnancy manifestation.