The concept of the public library defined by the Korean Library Association does not describe the current state of the Korean public library but describes the public libraries in the western society. Korean public library was formed after the western public library but it was modified and reconciled with the tradition of Korea. The difference between the concepts occured in the acculturation process of the Korean public library. According to the International Encyclopeadia of the Social Sciences, acculturation comprehends those phenomena which result when groups of individuals having different cultures come into continuous firsthand contact, with subsequent changes in the original cultural patterns of either of both groups. Korea opened its door to western world in 1876, and it began to contact with the western world. As the consequence, the concept of the public library of the West diffused to Lee Dynasty which were characterized by the confucianism and the extended family system. These two characteristics were against the public library concept and it could not function as it was and it had to be modified to fit to Korean society. The American public library was formed by the diffusion of English public library. The concept fitted in the colonial American society which was characterized by the Christianity and nuclear family system. Religion and family life were closely knitted together and they contributed much to the formation of the American public library. Also the society needed various information to form their new nation. The need of the public library grew and the public library repidly developed as the American society was urbanized and industrialized. The changes of Korean public library has passed the following process of acculturation. 1. The Korean culture contacted with Western world. 2. The public library concept diffused to Korea, but the people were illiterate and the need of the public library was for the preservation of the old books. The collection was not for people. 3. The function of the public library in Korea was altered slightly as several intellectuals who formed the first modern public library tried to literate Koreans as a means of liberation :from Japan through the library service. 4. The traditional libraries such as sodandg and hyangyo disorganized and finally disappeared as the traditional elements of the culture disappeared and the new cultural elements prevailed in Korea. 5. When the traditional elements of culture were disorganized, a reinterpretation of the diffused culture appeared. With the appearance of the vouth group which was not existed in the traditional society, cultural facilities for them were needed. They began to use public library as their reading rooms. This pattern has been institutionalized ever since in Korean public library. 6. When the new element of the culture spread, the traditional cultural elements react against this element. As the new public libraries sprung out, there were movements to restore the old Korean tradition of the family libraries and Hyangyo to counteract to the new libraries. This movements were not successful and they all disappeared as they could not keep up the rapid social change occurred in the Korean society. 7. In the process of the cultral change, cultural lag occurred between the public library and the users who could not adopt to the new library. This has been continued to the present time. 8. This diffused concept of the public library was modified and became native to Korean society. However, the acculturation of the public library concept has not changed the traditional ideas of Korean people and their behavior. The Korean society recently has been changing rapidly and the function of the Korean public library is improving accordingly; 1. The extended Korean family system is disorganizing. As the consequence, the public library could substitute the family system offering information and recreation service, etc. 2. The growth of educ..