Abstract:1. A simplified method to determine the oxidation stability of humus is proposed,in which the total organic carbon is oxidized by digestion with 0.4 N K2Cr2O7-1:1 H2SO4 mixture, while readily oxidizable organic carbon is oxidized by more dilute 0.2 N K2Cr2O7-1:3 H2SO4 mixture. Both are boiled for 5 minutes in oil bath with a temperature about 170-180℃ and 130-140℃ respectively.