Glucoamylase production was carried out under solid state fermentation by Aspergillus niger NCIM 616 has been investigated using three different Sorghum vulgare varieties as substrates. The solid state fermentation medium containing Sample-1 as a substrate yielded the highest enzyme activity. We purified enzyme from the culture supernant by ammonium sulfate precipitation, DEAE- Sepharose column chromatography. The molecular weight of purified enzyme was estimated to be 74KDa by sodium dodecyl sulfate- polyacrylamide gel electrophoresis. Maximum enzyme activity 82±2 U/g of dry Sample-1 was achieved under optimum growth conditions. The optimum conditions were incubation period 72h, inoculums size 15% (by mass per volume) having 107-108 spores/ml, incubation temperature of 400C and pH of 5.0.