Take S Ⅱ layer group in north development area of Daqing oil field as an example,it's studied that what is Stochastic inversion technique and its application to describe channel sandbody subtly.The study has shown that:In the vertical,there are large differences between the stochastic inversion results coincidence rate of sandbody of different thickness:The sandbody of over 3 metres,its coincidence rate is 98.6%,;The sandbody of 2~3 m, its coincidence rate is 79.1%;less than 2 metres,its coincidence rate is 71.5%;in the plane,the average coincidence rate of all sedimentary units can reach more than 75%,and the coincidence rate of delta distributary plain subfacies is higher than that of inner front subfacies.With the logging curve and inversion results,combinating well and seismic the channel trend,the single channel sandbody boundary in compound channel sandbody and the superimposed relationship between interwell sandbody ,can be described subtly.