Abstract: The killing effects on Galla were examined by using the extractant from Allium Sativum L.(AS), Melia azedarach L.(MA) and Sophora flavescens Ait(SF). The results showed that the mortality rate reached 70% when Galla exposed to the extractant from AS(8 mg/L) for 48 hours, the mortality rate reached 90% when Galla was treated by extractant from MA(80 mg/L) for 48 hours, and the mortality reached 90% when Galla was treated by extractant from SF(22.4 mg/L) for 96 hours. The LC50 of the extractant from AS, MA, SF were 4.96 mg/L, 37. 46 mg/L and 45.60 mg/L, respectively. In conclusion, the killing effects on Galla of the 3 plant species were ranked as AS＞MA＞SF.