to repressing the population of Plutella xylostella pests so that it brings good mustard plants. The research was carried out in April until June 2016. Located in the village of Tamantirto, district of Kasihan, Bantul district, Yogyakarta This research aims to know the proper concentration of mimba leaf extract on concentration special region Province. The used research method was Complete Random Design (RAL) with a single factor which comprises 6 treatments including control and comparator. Each treatment was repeated 3 times. The treatments to be tested consists of a mimba leaf extract with concentrations of 100 g/l up to 400 g/l. Chemical pesticide Profonefos 2 ml/l and control used as comparison. The results show that the treatment mimba leaves 300 g/l concentration most effective to control Plutella xylostella pests, with 16,16 leaf rate and the weight of plants is 115,84 gram