Abstract: The effects of confining pressure, density and water content to dynamic young's modulus of soils have been studed by resonant column method, the obtained rules are agree with those from stress-strain method. A comparison was made between the two test methods, and the differences between the two are significant. It has been noted that the reason may be the difference of the principle and proceedure between the two test methods, and may also be the effect of the number of vibration.