Angular momentum (/) effects on mass yield curves were studied for the fission from the same compound nucleus (CN) 239 Np of the same excitation energy but with different angular momenta, produced by the 7 Li+ 232 Th and p+ 2M U reactions. The effects were examined only for the complete fusion-fission events after careful estimation of the contribution of incomplete fusion-fission. It is found that the width of the whole mass yield curve is larger while the peak-to-valley ratio is smaller for the 7 Li+ 232 Th fission at the same excitation energy (E x ) of the CN, the former value increases while the latter ratio decreases with Ex. Statistical model calculations incorporating angular momentum dependent fission barriers were made to reproduce the observed cross section data of evaporation residues and fission. The observations can well be explained if the angular momentum dependence of fission barriers is taken into account in the competition process of fission and neutron evaporation in the decay of a compound nucleus except the observed trend of the width of the mass yield curve which could not be explained straightforwardly.