Objective To investigate the role of apoptosis in the pathogenesis of simian acquired immunodeficiency syndrome (SAIDS), we cloned the cDNA fragment of Fas gene in Rhesus monkey. Methods We extracted total RNA from inguinal lymph nodes and designed the upper and low primers according to the Fas gene of human. The fragment was obtained by RT-PCR, and then cloned into PGEM-T Easy vector Finally, the positive clone was sequenced. Results We first cloned the Fas gene of Rhesus monkey, the encoding sequence is 1 005 bp.The sequence was submitted to GenBank, accession number is AY007572. Conclusion The length of encoding sequence in Rhesus monkey Fas gene is different from the homologous genes of human and cynomolgus monkey which have already been submitted to GenBank.