This paper verifies which can maintain the postal universal service more efficiently among public corporation and privatized entity, through a comparative study between the case of Australia (public corporation) and the case of New Zealand (privatized company). We think this comparative study is an adequate case because, as we know well, these countries' geographical, historical and cultural constitutions or backgrounds are much similar, and their postal reform years are not so much apart from each other (1987 and 1989). As the result of our comparative study, we show the fact that, in the certain period (5〜6 years in our case) after reforms, a public corporation would definitely be more effective than a privatized entity as regard to maintaining universal service. However, from a long-term viewpoint, it would not be able to be declared clearly which are more effective.