[en] In these five years, the integral studies by D-T Neutron Source were carried out mainly to resolve the problems of fusion reactor neutronics. In addition to RTNS-I, OKTAVIAN, FNS and LOTUS were newly built for this area. Recent remarkable progresses in several fusion neutronics integral experiments are introduced here as well as to the neutron source properties and experimental methods. Those new machines have the very similar neutron intensity of 5x10¹²n/s order, and proved that their neutron intensities were enough to resolve the problems concerned with neutron spectrum. However, to measure the Tritium Breeding Ratio directly, it may be helpful for use to have higher intensity with nearly point-source characteristics. RTNS-II with the highest D-T neutron intensity of 6x10¹³n/s has mainly served for the fundamental studies of radiation damage, however, it has been sometimes very useful for fusion neutronics integral experiments. (author)