Abstract: Total protein of the leaves of Ammopiptanthus nanus was extracted,the buffer solution system was established which can obtain max leaves proteins from A.nanus.All protein groups were isolated by DEAE₅₂-C,whose molecular weights(14-90 kD)and purities were measured by SDS-PAG.The results of relative percentage of amino acids revealed the genetic consistency of the different species.Four protein groups were identified as antifreeze proteins whose thermal hysteresis activities(THA)were 0.4℃,0.33℃,0.48℃ and 0.15℃,respectively.This was evidences of discovery of antifreeze proteins in A.nanus.