In this paper the datas of Hi-tech companies of twelve deputy provincials are selected. And the competition ability of the Hi-tech companies in nanjing is discussed based on the comparative analysis on the total, per capita, economic and scientific indexes. All of the results indicate that the Hi-tech companies in nanjing are more competitive in some indexes, such as per capita output value, labour productivity and so on. But the the indexes of export scale and R&D financial input have their drawbacks.