Abstract: The analytical method of organic acids in the oxidation tests and oxidized products of kerogens is set up on the basis of a large number of indoor conditional tests.And for the first time,different typed kerogens from the Sanzhao area of the North Songliao Basin are studied using this method.By means of detecting on various ions in different comcentration of the organic acid-soaked solution of fifty-four cores from three wells and analysing and studing meanwhile on the physical properties of rocks and the changing characteristics ofpore structure,it is found that 1)different typed kerogens have clearly different oxidation yields,and 2)the existeiice of organic acids plays an important role in the developing ofthe secondary pore space of reserviors.These experimental studies give us a preliminary understanding of the genesis of secondary pore space and provicle an important scientific basis for searching the developing areas of secondary pore space in future.