The research of the effectivitiness of lemongrass leaves powder (Cymbopogon citratus.) in order to controlling rice lice pest (Sitophilus oryzae L.). It purposed to investigate the effect of lemongrass powder application on rice lice pest. (Sitophilus oryzae L.), and to get the suitable dosage of lemongrass powder effectively. The research was conducted on July 2017 in Protection laboratory of Universitas Muhammadiyah Yogyakarta. The research that conducted using single factor method with environmental treatment design Complete Random Design (RAL). The treatment that tested consist of five (5) treatments, there are 0 gram/50 grams of rice, 2 grams/50 grams of rice, 4 grams/50 grams of rice, 6grams/50 grams of rice, 8grams/50 grams of rice. Every treatment repeated till four (4) times and every repetition consist twice (2) repetition until the total there was 40 units. The observation that have been done on the level of rice lice rejecting parameters, mortality, efficacy, mortality speed of rice lice pest, the rice quality test. The result of this research show that the application of lemongrass powder are causing the rice lice pest’s body become stiff then it causing rice lice pest died. The treatment with dosage 8 grams/50 grams of rice produce rejecting level 23,0%, mortality 80,0%, efficacy 67, 6% and mortality speed was 2,97 the highest and economical value of the materials so the best treatment is dosage grams/50 grams of rice which produce rejecting level 19,3%, mortality 57,5%, efficacy 37,5% and the mortality speed 1,19%.