Fifteen compounds, including five new phorbol esters ( 1 - 5 ) and ten known metabolites were isolated from the leaves of Croton tiglium . The structures of new compounds 1 - 5 were determined by comprehensive analysis of the HRESIMS, IR, 1D and 2D NMR spectral data. The isolates were assayed for their larvicidal and α -glucosidase inhibitory activity; results suggested the new compounds 1 - 4 possessed significant insecticidal activity, inhibiting the Plutella xylostella with LC 50 values ranging from 0.081 to 0.114 μg/mL, while the sesquiterpenoids 11 and 15 showed noticeable α -glucosidase inhibitory activity with IC 50 values of 11.27 and 8.13 μM, respectively. • Five new tigliane diterpenoids were isolated from the leaves of Croton tiglium . • The new tigliane diterpenoids with unsaturated long-chain esters were obtained in Croton tiglium for the first time. • The new tigliane diterpenoids with unsaturated long-chain esters were firstly found to possess significant larvicidal activity. • The isolated sesquiterpenoids were found to possess remarkable α -glucosidase inhibitory activity.