Goniothalamus macrophyllus (Blume) Hook. f. & Thoms. is a plant widely distributed in Malaysia. The aim of this study is to identify compounds from the roots of G.macrophyllus. The ground roots were extracted with aqueous methanol and partitioned sequentially with n-hexane, chloroform and butanol. Purification from this extracts afforded six compounds with two new compounds, namely goniolandrene-A (1), -B (2). The absolute configuration of goniolandrene B (2) was established by circular dichrosim. The compounds were cytotoxic against the P388 cells with IC50 values ranging from 0.42-160 μM. Goniothalamin (3) exhibited the highest inhibition of 0.42 μM.