The modern retailing industry has shown a great impact to the enhancement of economy in Taiwan. in consequence, its financial structure becomes an important issue as long as the performance measurement is concerned. The current research described in this paper contains two parts. The first part is to present an empirical investigation where financial index is considered to measure the retailing performance. The second part is to examine the effect of financial index on sales and gross margin. The technique of Data Envelopment Analysis (DEA) is utilized to derive the efficiency and multiple regr5ession analysis to disclose the effects. The inputs as the independent factors are current assets, the number of employees, inventory investment, and promotion expenses used in the analysis while the outputs as the dependent factors are sales and gross margin. There were remarkable results: (1) the averaged efficiency was 0.7454 which, generally, did not show a good performance, (2) retailers in the group of vehicle apart and supplies performed the best, (3) retailers in the group of fabrics, cloths, and apparel accessories performed the worst, (4) current assts, the number of employees, and promotion expenses showed significant effects on both sales and gross margin. Other research results and findings were addressed and implication discussed in this research also.