With a rising number of Instagram users, Instagram has become a marketing tool of organizations. For influencer marketing, sponsorship disclosure is a critical issue to consider. This study investigates the effects of sponsorship disclosure on Instagram user’s brand attitude and purchase intention. In order to identify these effects, resistance theory and persuasion knowledge model were integrated. This research used an online experiment and found that activated persuasion knowledge of Instagram users had a positive response of cognitive (source of derogation) and negative response of affective (negative affect). Based on the results, theoretical and managerial contributions and as well as future research are discussed.

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