Abstract: An experiment was conducted to analyze on the low molecular weight organic matters(LMWOM) in cow dung composted production with/without NMF inoculants by Gas ChromatogramMass Spectrum(GC).The results have shown that there are a large number of low molecular weight organic matters in these productions.As far as these organic matters are concerned,there are as much sixteen kinds of low molecular weight organic acids and Aldehyde,Alcohol,Ketone,Carboxylic acid,Carboxylic acid,Furan,Pyrazine,Fat hydrocarbon,sulphide and so on.The results have also shown that the content of Aldehyde,Alcohol,Fat hydrocarbon,Carboxylic acid,Furan,Pyrazine,sulphide in composted production amended with NMF inoculants increased 6.5%、9.2%、5.7%、15.6%、9.8%、11.3% and 28.6%,respectively.But Carboxylic acid and Ketone decreased by 11.4%,and 15.5%.As far as the total content of low molecular weight organic matters were concerned,it increased by 42.8%.This study had supplied the basic materials for the judgement of quality of organic fertilizers.