¡§Brand¡¨ is not only the most valuable asset, but also a powerful marketing tool for the enterprises. As progressing of marketing management, co-branding strategy which combines two brand partners can bring profits and sustainable competitive advantages to the corporate enterprises. Between-partner congruity (BPC) has been identified as an influential factor in the success of a co-branding strategy, and there are two mainstreams of research in co-branding strategy exist: (1) linear relationship between BPC and co-brand evaluation or (2) reverse-U curve relationship between BPC and co-brand evaluation. Based on such inconsistent findings, this study explores how hedonic shopping motivation and ad focus affect consumers¡¦ evaluation toward the co-branded product through different levels of BPC. The present study employs an experimental design to investigate the effects of BPC (high vs. moderate vs. low), ad focus(product vs. brand), and hedonic shopping motivation (high vs. low) on consumers¡¦ evaluation of co-branded product. A 3x2x2 factorial design is conducted. Six different scenarios are established through virtual co-branded cell phone advertisement. Median split is used to distinguish consumers into high and low hedonic shopping motivation. Consumers¡¦ evaluation is measured by purchase intention, attitude toward the co-branded product, and perceived quality. The results indicated that when the ad focus is product, there is a linear relationship between BPC and consumers¡¦ evaluation. However, when the ad focus is brand, the aforementioned relationship becomes weaker. The linear relationship is robust for those consumers with low hedonic shopping motivation. On the other hand, when the ad focus is brand, moderate BPC would lead to higher purchase intention and quality perception for consumers with high hedonic shopping motivation. Based on the above findings, influences of ad focus should be considered when different levels of BPC are determined. Marketers should choose the right focus for higher evaluation toward co-branded products.