The effect of inhibitors such as hydroxylamine and sodium azide on laccase was monitored. Three different concentrations of hydroxylamine and sodium azide follows as 0.2, 0.3 and 0.4 mM were added in the reaction mixture containing 0.4 ml of 5 mM ABTS and 0.8 ml of culture supernatant and incubated at pH 5.0 temperature 60 ◦C for 10 min and reaction velocity was measured.