This research aims to analyze the factors that influence traveler to book open-trip service through open-trip marketplace website. The collection data method that is used is online questionnaire. This research manage to collect 58 travelers who have booked on an open-trip marketplace website. The collected data then analyzed using Partial Least Square (PLS) method and using SmartPLS 3.0 software to analyze the data. The result of this research show that traveler’s intention to book open-trip service through open-trip marketplace website is directly influence by attitude toward merchant and indirectly influence by merchant familiarity with an intermediate factor attitude toward merchant. Other than that, this research also show a significant relationship between source credibility with attitude toward E-WOM, and also fulfillment and system availability with attitude toward channel.