This paper studies the historical status of the CISG from the position of the unified model of international trade law. The international trade law’s unification movement has lasted a century, and CISG is the highest achievement. There are three unified models of international trade. Those are world law model, law of nations model and model law. CISG belongs to the law of nations model which is similar to ancient Roman law of nations. This is the most effective model in the unification of international trade, because the world model is too far ahead, and model law is too conservative. It is CISG just right to use the law of nations unified model Therefore, it is playing a great role in the process of unification of international trade law. It has its historical status that should be properly evaluated.