Abstract: It is one of the difficult problems in oil and gas exploration to predict the thin sand thickness. This paper introduces the linear transitional theory. Based on such theory, the linear transitional wedge model which is more closely to the practical medium is established. Following the forward modeling in time domain and the characteristic analysis of its response in frequent domain, a thought of thin sand thickness predicting based on turning frequency is proposed and a relevant working flow is also formed by the practical thin sand thickness prediction. Validated by the drilled-well data, it is found that the predicting results of the thin sand spatial boundary and thickness are coincide with the reality and that the method has a good future by widely using.