Efficient porous silicon organic vapors sensors werefabricated byemploying a multi-porous silicon layer (mPSi) within (Au/mPSi/n-Si/Au) sandwich structures. Based on the morphological nature and the resistivity of resulting (mPSi), the mechanism of current flow in the sensor was analyzed. The SEM images of (mPSi) layer reflect the formation of complex porous and mud-like structures. The mud-like structure consists of connected and non-connected trenches whilethe pore-like structure consists of different pore sizes formed inside this structure. The current response is governed by the silicon channel between the adjacent mud’srather than the silicon nanowires between the adjacent pores.