Spectrophotometric determination of isonicotinic acid hydrazide sodium methane sulfonate was examined and a new method has been established. Isonicotinic acid hydrazide sodium methane sulfonate reacts with acetylacetone solution (NASH Reagent) to produce a yellow dye, which exhibits absorption maximum at about $412;m{mu}$. Limits of masurement of isonicotinic acid hydrazide sodium methane sulfonate was $20-100{mu}g/ml$. By this method isonicotinic acid hydrazide methane sulfonate can be determined in the presence of isonicotinic acid hydrazide.