Forty years have passed since the UNCLOS was adopted and it is necessary to reexamine its successes and failures. This article will set out to check the four legislative features of the UNCLOS and then make some suggestions. From the aspect of legislative technique, the UNCLOS is extensive with an ambitious framework but is vague in details. From the aspect of a principled position, meanwhile, its provisions are mainly beneficial to countries with long and unimpeded sea lines but not to landlocked countries, short coastlines, or an impeded outward extension. From the aspect of rights and interest division, the division of maritime rights and interests of countries in the UNCLOS is not operational in practice. From the aspect of dispute resolution, it has constructed an ambitious mechanism accommodating various international judicial institutions, which is, however, too complicated, lacks focus, and has loopholes. The international community should consider revising and improving the Convention in view of certain shortcomings and deficiencies in its legislative features