The strategy of regional industrial specialization is empirically evaluated by examining the relationship between regional industrial structures and economic performances. The regional industrial structure is measured by three industrial diversity indices such as ogive approach, entropy maximizing approach, and economic growth and employment instability in 12 regions is analyzed. According to the time series analysis, we found that the region with more diversified industrial structure experiences more stable in employment. Otherwise, the growth rate of the region with more simplified industrial structure is higher. Therefore, the strategy of industrial specialization is implemented in order to pursuit a rapid economic growth in the short run.