The purpose of this study is to analyze the relationship between socio-economic development and migration among different counties in Taiwan. Based on data of 1979 and 1988 this study examines the hypothesis that socio-economic development had an impact on migration. Using the method of c1usteranalysis, we identified six c1ustersof socio-economic development of counties in 1979 and in 1988 respectively. The six c1ustersof socioeconomic development in 1979 are: (Ⅰ)Traditional Agriculture Cluster, (Ⅱ)Early Urbanized Cluster, (III)Pre-Accelerative Urbanized Cluster, (IV)Mid-Accelerative Urbanized Cluster, (V) Post-Accelerative Urbanized Cluster, and (VI) Stable Urbanized Cluster. And, the six c1ustersof socio-economic development in 1988 are: (Ⅰ)Early Urbanized Cluster, (Ⅱ)Pre-AccelerativeUrbanized Cluster, (Ш)Mid-Accelerative Urbanized Cluster, (IV)Post-Accelerative Urbanized Cluster, (V) Mature-hood Urbanized Cluster, and (VI) Stable Urbanized Cluster. The examination of the relationship between socio-economic development and migration indicates that the higher the socio-economic development level, the higher the in-migration rate. In addition, the larger the difference between socio-economic c1usters,the bigger the migration stream. The hypothesis that the migrants move toward areas with better socio-economic opportunities is supported.