<p>The purpose of this study was to examine the effect of Customer Satisfaction and Loyalty on Online Purchasing on E-Commerce Sites on Quality and Trustworthiness of Electronic Services (Survey on marketplace users in Bogor City and Regency, West Java). The advancement of electronic platforms, as well as customer retention and loyalty when making online E-Commerce purchases, was examined in this study with a total sample of 350 millennial generation respondents, test questionnaires were circulated using Google Forms to online buyers using marketplace facilities in the city and district of Bogor, West Java Province. , Indonesia. Then the data were analyzed statistically using the partial least square approach - structural equation model (PLS-SEM) using SmartPls. 3.0 program. The results showed that Electronic Service Quality has a positive and significant effect on Customer Satisfaction and Loyalty, Trust has a positive and significant effect on Customer Satisfaction but has no effect on Loyalty, Customer Satisfaction has an effect on Loyalty, and Customer Satisfaction has an effect on Electronic Service Quality. According to the findings, Marketplace should expand its offering and partner with other leading online service providers.</p>