The most favorable nitrogen source for the production of protease by Aspergillus oryzae PF was 2% soybean flour among sodium nitrate, ammonium sulfate, defatted soybean, skim milk, casein, peptone, and yeast extract. The production of protease from A. oryzae PF was higher at the concentration of 2% lactose than at variable concentration of glucose, sucrose, soluble starch, corn starch, potato starch, wheat starch, rice starch, cellulose, and gum arabic. Protease production was affected by the concentration of KH2PO4, Triton X-100, CaCo3, and MgSO4, and it was the highest at the highest at the concentration of 3% KH2PO4, 0.01% Triton X-100, 0.3% CaCO3, and 0.06% MGSO4.