The curves demarcation of neutron counting and the soil moisture content were central contents in determining soil moisture by neutron probe. In order to draw up the curve which could been applied in the different soil profile, soil texture, organic matter content and soil profile water content. Through packing up the literature about curves demarcation of neutron counting and the soil moisture content, the emphasis factors were analyzed from working principle of neutron probe. It was sum up that the problems were fell across in measuring soil water content. According to neutron counting value not only related with soil moisture content, moreover also related with distance of neutron probe and the position where moisture content was surveyed, the accurate demarcation water content methods were proposed during soil profile water content changing in layer.