Abstract：In some projects using cement to improve soft soil foundations，it is found that organic matters in soil have great influences on the stabilization effects when the organic content soft soil is high，which makes the strength of stabilized soil not reach the expected one. So some indoor studies have been performed on this problem. It is found that the organic content of soil is changed by adding substance with high organic content in order to study the influence of organic content on the consolidation effect of cement，and the progress of consolidating soft soil with cement is modeled indoors. Then，the mechanical indexes of soft soil with different organic contents are determined with direct shear test and unconfined compression test after being consolidated by cement. A further analysis on the effect of organic matter in cement consolidating soft soil is made on the basis of soluble salt，exchange capacity of cation and microstructure. The derived results show that the more organic matters there are in soft soil，the worse the mechanical properties are. Moreover，data of soluble salt，exchange capacity of cation and microstructure pictures all make a compensating explain to the mechanical results，which exert the influences of organic on the effect of consolidating soft soil with cement much clearly. It can provide reference to the practical engineering projects.
