Marketplace is an intermediary platform between sellers and buyers to process product transactions online. This study aims to determine and analyze the effect of promotion, trust, security and quality of information simultaneously and partially on purchasing decisions on the Shopee marketplace. The study used a quantitative approach with primary data, which was obtained by distributing online questionnaires. The independent variables consist of promotion, trustworthiness, security and quality of information. The dependent variable is the purchase decision. The population is college students in the Depok area who have bought in the Shopee marketplace, as many as 134 respondents were used as samples. Using Multiple Linear Regression analysis tool, F test and t test, Determination. The results obtained are that promotion, trust, security and quality of information simultaneously influence purchasing decisions on the Shopee marketplace. Promotion has no partial effect on purchasing decisions on the Shopee marketplace. Meanwhile, trust, security and quality of information partially influence purchasing decisions on the Shopee marketplace.