[en] The use of gamma radiations for improving protein content of rice variety Pelita I/1 yielded mutants which were consistently high in protein level. However, only a very few have a good TD value. One is mutant 627/5-PsJ which has a good chance to be officially released because it is resistant to BPH, has high yielding potential, good eating quality, early maturity and high tolerance to salinity. The environmental conditions, such as heterogeneity of soil, amount of N-fertilizer and reproducibility of method for protein determination have significant effects on the variability of protein content in certain genotypes of rice. (author)