Searching for agrochemical from 3 species of weeds in the family Euphorbiaceae, namely Euphorbiace hirta, Euphorbia thymifolia and Euphorbia heterophylla. The crude extracts of their parts were tested 2 activities, rice growth inhibition of rice (Oryza sativa cv. RD 23) and Brine shrimp cytotoxicity lethality. The results showed that the dichloromethane crude extract of the stem part of Euphorbia heterophylla inhibited 100% of rice growth (Oryza sativa cv. RD 23) both leave sheath and root length at 0.5 g of the crude extract per solution 3 ml. The active fraction was fractionated by column chromatography using rice growth inhibition as guide for further fractionation, found that the fraction III C was the best fraction, which inhibited 63.32% (leave sheath), 59.98% (root length) of rice growth (Oryza sativa cv. RD 23) at 10,000 ppm and gave high activity with brine shrimp (LC50 9.09 mu g/ml). The Purification of this fraction gained two compound; Compound 1 and Compound 2. By mean of the spectroscopic identification, Compound 1 proved to be lupeol acetate and Compound 2 was a triterpenoid. From rice growth inhibition activity concluded that Compound 2 was an active compound. It was inhibited 39.64% (leaf sheath) and 55.54% (root length) at 10,000 ppm.