Total RNA was prepared from pituitary of bovine.mRNA was isolated from the total RNA. cDNA was synthesized as template used in PCR for amplification of cDNA for α subunit of bovine follicle stimulating hormone. Sequence analysis showed that the obtained cDNA fragment is 380 bp and all these nucleotides except one coding for Lys of No.24 are as same as that Erwin reported. Comparison of bovine, human and rodent indicated that the amino acid and nucleotide sequences of the α subunit in these mammalian species are highly conservative.