Marketplace is any activity related to transactions or trades carried out using electronic devices and internet networks or better known as online trading or online buying and selling. Another negative thing that arises from the existence of Marketplace is when consumers buy a product but when it arrives in the hands of the consumer, the product does not match the information listed on the product. The many Marketplace available make consumers face difficulties in choosing the best e-commerce to shop. The variety of assessments or ratings that are already good enough is also a level of difficulty for consumers to choose the best Marketplace. This study aims to find out how to determine the best Marketplace using the MOOSRA and ROC methods and find out what criteria are used in the selection of e-commerce. The methods used in this study exist. In this study, the best marketplace was selected by applying the Multi-Objective Optimization On The Basis Of Simple Ratio Analysis (MOOSRA) method. The selection process in this study uses four Marketplace alternatives, namely Shoope, Lazada, Bukalapak, and Tokopedia, as well as four criteria, namely, ease of use, delivery, service quality, and price. In this study, the Rank Order Centroid (ROC) method was also used to determine the weight of the criteria. The results of the study show that shoope is the best marketplace alternative choice with the highest performance score of 17.13648, followed by Tokopedia at 15.30619, then Lazada at 15.06473, blibli 14,957 and the last one is bukalapak at 14.83551
