The dissertation accounts for that the basic reason that the accounting policy choice characterized of opportunism is the native defect of the contractual theory . another important factor is that the inside and outside mechanism of restriction of accounting policy choice is out of balance 笔者认为,契约理论下的会计政策选择之所以具有机会主义特征与契约理论自身的缺陷有关,同时会计政策选择内外约束机制的失衡及其会计质量水准不高也是重要的因素。