Three new diterpenoids, including one clerodane diterpenoid 1 and two linear diterpenoids 2 and 3, were isolated from the aerial parts of Croton laui, along with four known compounds 4-7. Structural elucidation of the isolates was performed by spectral methods such as 1D and 2D NMR, IR, UV, and HRESIMS. Compound 1 exhibited cytotoxic activities against Hela and MCF-7 cells with IC50 values of 14.5 and 62.5 mu M, respectively.