Abstract: The compacted minimicritic limestones of the Upper Qiulitage Group( Lower Ordovician)are one of the prospecting targets in the north Tarim Basin.The type of the reservoir pores is dominated by micropores,attributed to an unconventional type of suture-micropore reservoir.The micropores formed preponderantly under corrosion,particularly the deep corrosion.It is a compacted limestone reservoir with micropores discovered recently in the country,which would be significant for it provides scientific basis for petroleum exploration,and renew the types of carbonate rock reservoir in China.Meanwhile it makes the studies available on the origin and evolution of micropores.