Abstract: The interference factors in petroleum geochemical exploration are caused by the combination of natural geographical conditions,epigenesis and anthropological activity. The reliability of geochemical exploration and its effects in geology,to a certain extent,depend on the interference factors and the level of correction on them. However,the interference factors do not occur independently. Basically,a comprehensive study on various interferences in soil medium is made in the paper. In addition,multi-dimensional corrections for them are proposed for petroleum geochemical exploration. Getting rid of the pseudomor-phes of epigenetic geochemistry,the surface geochemical field would truely reflect the trace of subsurface hydrocarbon accumulations.