Abstract: The effect of parameters error in horizontal muiti-layered model used in location on depth determination is discussed both in theory and numerical experiment, and the consistent result is obtained. It is obvious that the errors in total thickness of earth's crust and layers, the deviation of lower iayers, parameters, the united layer and equal velocity ratio (Vp/Vs) used in layers etc. may lead to significant and complex affection which areno-liteable factors, generaly. It is sugggested that combinning data of waves travelling through various paths, mainly first P, S arrivals of direct and refracted waves trasmitting different layers, are useful for repressing the effect of model parameters' deviation on the error of depth tietermination, and the tocation method with direct waves only or sinlile layered crust method is useness for improving the location accuracy. Finally, the possibility of inverting 3-dimension crustal structure based on depth differences determined with data of various station-set is pointed out.