Abstract: The gerbil (Meriones unguiculatus)is a representative animal in desert steppe and the improtant host in natural focus of plague in Ningxia and Inner Mongolia.This investigation was carried out month by month during 1979-1980 in Taole.Ningxia.There are mainly four biotopes in this district;wasteland in the alluvial plain of Yellow River(I),wasteland between the agricultural field(II),the plain with dersert grassland(II),grassland inserted in sand dunes(IV).Tte results are summarized below(1) There were differences in the density in every month at the above four biotopes.The avera densities in III and I are higher (3.1-3.3ind/h) than that of the others(0.7-1.6ind/h).(2) One hundred and fifty nine gerbils weie rrarked and released, some of them can be migrated out at any time.(3) The dissecting of the 647 females indicated that the peaks of the pregnancy ratio and the reproduction index were in April, May and July but reproduction stopped in November and December.(4) Investigating the stomach contents of the 1226 gerbils indicated that their food habit generally take the leaves and stalks of the green plant in summer and live on grains and seeds of wild plant in autumn, winter and spring.(5) Subadults are the main component in age structure according to the investigation of 1258 individuals.