Effect of peanut (Arachis hypogaea) seed flour and its fractions on the growth of Streptomyces clavuligerus and clavulanic acid production in media containing soy meal, malt and mineral salts as the main substrates, was investigated. Peanut seed flour increased the clavulanic acid production by S. clavuligerus. Concentration of clavulanic acid in the media containing peanut seed flour, peanut meal, peanut oil, glycerol, peanut meal + glycerol, peanut protein + glycerol and control were 657, 391, 459, 463, 614, 668 and 467 mg/l, respectively. Concentration of clavulanic acid in the media containing peanut protein + glycerol and peanut seed flour were the most and clavulanic acid production in these media were 43% and 40% more than that of control, respectively. It was concluded that peanut and its fractions can use as suitable nitrogen and carbon sources for clavulanic acid production.