Abstract: Based on the geological mud logging data,combined with logging,production testing and other materials,the Tuoputai area Ordovician carbonate rock reservoir body in Taha oilfield has been carefully studied.The research indicates that the reservoir space is various,the effective reservoir space is mainly structural seam,and secondary pore as dissolution pore,hole and seam.Reservoir heterogeneity is strong,influenced by fracture obviously,horizontally distributed in north,middle part of fault zone,vertically distributed under Ordovician 0~60 m.The main porous space of reservoir is intergranular dissolution pore,intra granular dissolution pore,casts pore and the fracture.Considering the various types combination,the reservoir space structure type is divided into 3 kinds.The carbonate rocks reservoir matrix porosity and the permeability are relatively low,very difficult to constitute the effective reservoir space,therefore the whole growth degree of study area is not high,and it is distributed unevenly.