The search engine advertising (SEA) market has been developing rapidly in recent years． The empirical research on keywords biding strategy and performances in China，however，is very limited． Based on a unique dataset of Zhitongche SEA in Taobao． com，this paper applies an econometrics analysis to explore the relationship between keywords biding strategy and SEA performances． The multi-dimensional analysis indicates that increasing the biding price of keywords is more efficient in generating payback than increasing the number of keywords under equal costs． Meanwhile，considering brand information and specific products information during the keywords design is also helpful to raise the sales． The ROI of Zhitongche SEA reaches about 450% in this study，suggesting a good return of SEA in Taobao． com． This study contributes to the SEA theory with the empirical results from the pure ecommerce websites． It also provides managerial implications for advertisers to improve their keyword biding strategy in SEA．