Taking the Triassic middle oil-group of well AT1 in the Tahe Oil Field as example, the physical property, lithology and pore structure features of the main oil-producing reservoir were delicately described through multiple experimen tmeans. The middle oil-group in the region is divided into 2 sets of reservoir (7 and 9 mthick, respectively, oil storage pore ratioof 5-20μm) with relatively complete Bouma sedimentary sequence by mud interbed. Potential damages such as speed, acid and alkalinity sensitivities might exist inreservoir. Permeability features and exploitation quantity of the reservoir during different stages were proposed through experiments.