A chloroform-fumigation extraction—water bath method(CFEB) was developed for measuring microbial biomass C in waterlogged soils.Liquid chloroform was directly added to the waterlogged soil to be tested,which was fumigated for 24 h at 25℃ under normal atmospheric pressure and in darkness,and then were extracted with 0.5mol L^-1 K₂SO₄ solution.The extractions were carried out in 100℃ water bath for 45～60 min to remove chloroform residue before measuring TOC.Nonfumigation controls were extracted directly with 0.5 mol L^-1 K₂SO₄ solution.The method was tested on seven paddy soils which were incubated aerobically or anaerobically and compared with the standard chloroform fumigation extraction (CFE).The results of the tests were reliable and reproducible,suggesting that the CFEB is a rapid and effective method for measuring microbial biomass C in waterlogged soils.