At present,there are quite a few problems in the industrial development of Haikou City in Hainan province,such as unbalanced industrial development,no effective industrial agglomeration,and high energy consumption. With an analysis of the recent industrial development and structural changes as well as the location and resources in Haikou and from the perspective of its choice of regional key industries,this paper gives a case study of the problems concerning the income elasticity of demands,factor productivity( including labor productivity,capital profit rate and energy productivity) and industrial competitiveness advantages( good location quotient and comparative labor productivity as well as high market dominance index). It concludes that Haikou City should focus on the development of six major industries,that is,computers and communications plus other electronic equipments,the industry of electrical machinery and equipments,the industry of printing and the recording media,pharmaceutical industry,transportation facilities,and agro- food processing industry in order to achieve the maximum optimization of the geographic vantage points and resource efficiency for promoting the rapid socio- economic development in the future.