It was previously reported that yeast elicitor transiently increased oleanolic acid and ursolic acid in Scutellaria baicalensis suspension cultures and also doubled phospholipase $A_2$ ($PLA_2$) activity. Thus, $PLA_2$ was purified from the soluble fractions of S. baicalensis suspension cultures and the characters of the purified $PLA_2$ were identified. The $PLA_2$ was purified about 160 times compared with the starting soluble-protein extract from S. baicalensis suspension culture cells. The purified protein showed a molecular mass of about 43 kDa by SDS-PAGE. The purified plant $PLA_2$ had a neutral pH optimum (pH 7.0) and required $Ca^{2+}$ for activity. The $PLA_2$ activity was inhibited by mammalian $PLA_2$ inhibitors such as 5,8,11,14-eicosatetraynoic acid(ETYA) and arachidonyl trifluoromethyl ketone ($AACOCF_3$).