Oroqen is one of northern minority nationalities in China. The Oroqen has their own language but they have not yet created their own writing system. The Oroqen language belongs to the Tungusic branch of the Altaic language family. The present paper discusses the category of adjectival comparison of Oroqen. The paper summarizes the results of studies up to the present and gives the conclusion of fieldwork which had been carried out at Oroqen Autonomous Banner, Hulunbeir city from July to October in 2008. Oroqen has the category of adjectival comparison with four degrees which can be classified as positive, subtractive, additive, and superlative depending on different meanings and formations. And the methods used for expressing the degrees of the category include additional, repetitive, and postpositional means. The present author have also found a suffix that express the category of adjectival comparison of Oroqen language, which have not yet mentioned by others.