In order to reveal the biochemical basis for the pharmacological use of the antler velvet of Père David’s deer (Eluphurus davidianus), we analyzed the estradiol concentrations of velvet tissue samples. We collected velvet tissue from Père David’s deer, sika deer (Cervus nippon) and fallow deer (Dama dama). After extracting steroids from velvet tissue with ether, we analyzed the estrdiol concentrations using radioimmunoassay technique. We found that: (1) estradiol concentrations were significantly different in the velvet tissue of these three cervids (P<0.05) and (2) Père David’s deer stags had the highest velvet tissue estradiol concentrations, 105.29±27.53 pg/g. [Acta Zoologica Sinica 49(1):124-127,2003].