With the rapid development of Internet and E-Commerce in recent years, online sweepstakes have become one of the most favorite promotion tools. This study discusses the brand evaluation on interactivity of online sweepstakes,the complement of brand product-prize fit,the goal of brand product-prize fit and online users¡¦ demographics. This research adopts 2X2X2 experimental method and distributes online questionnaire, retrieving 387 samples and analyzing the data with SPSS 17.0. The results shows that the interactivity of online sweepstakes and the goal between the brand product and prize fit affect brand evaluation,but the complement of brand product-prize fit does not. Income and gender do not have moderating effect. Companies should held more highly interactive online sweepstakes and choose higher goal of brand product-prize fit product for prize.Thus,it will raise overall brand evaluation.This study therefore provides some practical advice to companies on online sweepstakes strategies in the future.