The late Cenozoic fluvio-lacustrine deposits in the Nihewan Basin, North China, have yielded a very rich source of paleolithic sites and mammalian fossils, which recorded early human activities and the evolution of mammalian faunas since the late Pliocene. The Pulu fauna, one of the Nihewan faunas (sensu lato), is located on the eastern bank of the Huliu River in the Nihewan Basin and contains mammalian fauna in the late Pliocene to early Pleistocene. Here, we selected the fluvio-lacustrine deposits containing the Pulu mammalian fauna to conduct detailed rock magnetic and high-resolution magnetostratigraphy studies, combined with biostratigraphic and lithostratigraphic results, to precisely constraint on the Pulu mammalian fauna. The results showed that the magnetic minerals in the fluvio-lacustrine deposits of the Pulu section are mainly magnetite, maghemite and hematite, with predominantly pseudo-single domain. The Pulu fluvio-lacustrine deposits recorded the early Brunhes normal chron, the Matuyama reverse chron, the Gauss normal chron and the late Gilbert reverse chron. The Pulu mammalian fauna was found during the pre-Reunion Matuyama chron and the post-Kaena Gauss chron with the age about 3.0 similar to 2.2 Ma. This study has extended the lower age of the Nihewan faunas to about 3.0 Ma. Furthermore, the paleoclimatic and paleoenvironmental studies in the Nihewan Basin suggested that the evolutionary direction of the Nihewan faunas were influenced by changes in climate and environment during the Pliocene and Pleistocene transitions, and Nihewan faunas evolved towards adapting to a cold and arid environment.