Two novel cassane‐type diterpenes, named magnicaesalpin ( 1 ) and neocaesalpin O ( 2 ), together with three known compounds, caesalmin D ( 3 ), caesalmin E ( 4 ), and neocaesalpin L ( 5 ), were isolated from the MeOH extract of seeds of Caesalpinia magnifoliolata Metc . Their structures were determined by spectroscopic methods, (1D‐ and 2D‐NMR, HR‐EI‐MS) and X‐ray analysis, as well as by comparison of their spectral data with those of related compounds.