In this study all kinds of Library Associations in Korea counted as Library Coperatives are surveyed under the categories of their collaborative activities as well historical developments. The results of this study are as follow : 1) The library cooperatives which have more working personnel are carrying out interlibrary cooperations more effectively, than those which have fewer working personnel. 2) The library cooperatives operating with established and realizable regulations or rules are more progressive in interlibrary cooperations than those operating with traditional practices or customary rules. 3) The library cooperatives with executing committee appear to be more progressive in interlibrary cooperations than those without it. 4) Both updating frequency of union catalog or union list and publishing intervals of supplementary editions are proved to be an important factor affecting the effectiveness of interlibrary cooperations. 5) Three of library cooperatives are employing the systems for payment of information provisions in interlibrary cooperations but the other library cooperatives are employing no payment systems, or not following such systems. By the results, six kinds of suggestions to improve the activities of korean library cooperatives have been expressed.