Abstract: In order to study stress sensitivity of unconsolidated sandstone reservoirs and simulate the influence of sanding to reservoir permeability,on the basis of man-made loose sand core and using experimental apparatus for stress sensitivity test,the variations in reservoir permeability and relative permeability under sanding or non-sanding conditions were simulated at various pressures and flow velocity in the stress sensitivity experimental study by using Synthetic core.It is indicated that permeability drop would be over 50% when the axial deformation exceeds 2% due to its large degree of compaction for the unconsolidated sandstone reservoir,and the two phase flow zone reduced from 55% to 20% while sanding could lower the reduction speed of the two phase zone.So the results showed that unconsolidated sand reservoir has strong stress sensitivity and moderate sanding could slow permeability drop and lower the reduction speed of the two phase flow zone so as to maintain well production capacity to some extent.