PI3K, phosphatidylinositol-3-kinase, is a specific lipid kinase family. It is associated with cell proliferation and survival..Class-IA PI3K is heterodimers composed of catalytic subunit (p110) and regulatory subunit (p85). p85α is the most abundant regulatory subunit of PI3K family. PI3K-p85α partial cDNA was amplified by RT-PCR from Inner Mongolia Cashmere Goat (Capra hircus) and sequenced. The molecular characterization of the PI3K-p85α gene was described. The amplified fragment is 1152bp in length, corresponding to a polypeptide of 384 amino acids residues with 45.4 kDa predicted molecular mass. The cDNA nucleotide sequence has 98% identity with regulatory subunit alpha (PIK3R1) of bovine and 93% identity with human. The goat PI3K-p85α patial cDNA is cloned.