The derivative of flavonoid compounds, artocarpin (1) and artonin M (2), were isolated from the root wood of Artocarpus altilis and from the root bark of A. kemando, respectively. Both plants originated from Lampung, Indonesia. The structure of the two compounds has been carefully determined by physical method and spectroscopy techniques of UV, IR, and NMR. The in vivo antimalarial test of artocarpin showed very good Plasmodium activity in female mice, with ED50 value of 34.88 mg/kg body weight (kgBW), whereas the in vitro antimalarial test of artonin M showed very strong activity with IC50 of 0.3 μg/mL (5.967 x 10-7 M).