In the face of uprising popularity and influence of power blogger as an opinion leader in the contemporary consumer society, an experimental study was conducted to understand how on-line consumers are likely to respond to power blogger ’s product endorsement. In specificity, two primary domains of power blogger were the main focus of this study as the key psychological underpinnings of how power blogger influences consumer’s acceptance of brand endorsement: endorser dimension and message dimension. Here, the endorser dimension consisted of five key factors, that is, endorser likeability, endorser familiarity, endorser similarity, endorser expertise, and endorser trustworthiness. The former three endorser factors represent endorser attractiveness, and the latter two endorser factors represent endorser credibility. The message dimension consisted of six factors: message accuracy, message usefulness, message two-sidedness, message novelty, message diversity, and message experience. The former three factors of message mainly reflect functional, utilitarian characteristics of message, whereas the latter three factors of message generally indicate emotionality and sensory aspect of message.As a further step, two situational factors were introduced as the main moderators that account for the relative effects of endorser factors and message factors associated with power blogger on consumer’s- 114 - brand acceptance. The first situational factor tested was usage context which is driven by either utilitarian consumption motives or hedonic consumption motives. The second situational factor included was temporal distance construal level which is typically characterized by near future construal and distant future construal.One hundred forty-one students from Dongguk university were recruited for the study, and the experimental design was a between- subject factorial design consisting of usage context (utilitarian usage context versus hedonic usage context) and temporal distance construal level (near future construal versus distant future construal). A popular Korean fashion model who has been generally known for high blog activities was selected as the power blogger and a hypothetical backpack brand “Meters” was introduced as the testing brand. A 5-page blog was developed as the testing blog material in which the Korean fashion model provided various kinds of information about the new backpack brand and endorsed it. Students were randomly assigned into one of four experimental conditions and asked to read and imagine a given usage scenario that specified one of near future utilitarian context, distant future utilitarian context, near future hedonic context, and distant future hedonic context, respectively. After then, participants were instructed to read the 5-page power blog by the Korean fashion model that endorsed “Meters” backpack. Finally, they indicated perceptions of endorser factors, message factors, brand attitude, purchase intention and recommendation intention in order.The study findings show that trustworthiness and likability as the endorser factors played a primary role in determining brand acceptance regardless of situational context. In terms of message factors, message usefulness and message two-sidedness had increasing effect on brand responses (i.e., brand attitude, purchase intention) in the utilitarian context and distant future contexts, whereas message diversity and message novelty showed increasing impact on brand responses in the hedonic context and near future context. Therefore, it can be concluded that endorser factors and message factors exert differential impact on consumer responses to brand endorsement by power blogger depending on situational contexts. This study suggests that marketers need to take into consideration the characteristics of situational context (i.e., usage context, temporal distance construal level) when cooperating with power blogger for product endorsement. In particular, marketers may need to prioritize the likability and trustworthiness of power blogger as the power blogger’s personal quality across various situations, whereas the usefulness, two-sidedness, diversity, and novelty of blog content should be regard as the key factors in enhancing message effectiveness depending on situational context.