Title: Consumer’s behavior and trust in E-commerce. Authors: AMIMEUR Rachel and NOCERAS MULET Caterina Supervisor: LJUNGQUIST Urban Level: Bachelor Thesis in Business and Administration, Marketing Key words: E-commerce, consumer’s behavior, buying behavior, Trust, pure players… Purpose: The purpose is to explore how people working in E-commerce can encourage customers purchase decision on internet by improving customer trust during the purchase. Frame of references: First of all, we give a definition of consumer behavior following by characteristics affecting it and a description of different king of buying behavior. Then, we describe the buyer decision making process for a known product or an innovation. We bring some knowledge about trust in E-commerce. Finally, we present our conceptual framework. Method: First, we explain the methodological approach and then the research design. After this, we explain which research method we took and why. Finally, we explain the writing of our survey. Conclusion: Trust in E-commerce can be brought through for elements: product quality, payment security system, E-customer relation management, website quality and time of delivery.