Abstract: Isotopic neutron source well logging is a technology，through wich the geological and project parameters of porosity, oil saturation and element content can be determined by recording neutron or gamma ray, which are produced through the reaction of neutron generated by isotopic neutron source with nuclei in borehole and formation material. Isotopic neutron source well logging technology was sketched out, the development course, technical aspect and application of isotopic neutron source well logging were summarized and the development prospect of isotopic neutron source well logging was looked ahead.