The purpose of this research is to build a web-based point of sale information system that can help at Pelangi Sungai Lilin shops. Buying and selling activities that are still manual and very simple and are considered less effective, therefore we need an information system that makes a buying and selling transaction that issafe and effective and makes it easier for the store to control good and efficient data management. Making a web-based point of sale program is useful forshop owners in order to minimize errors in every purchase activity as well as the right stock information. In making this system using the (RUP) method so that in building this program it starts from 4 phases or stages, namely inception, elaboration, construction and transition. In the end, a webbased point of sale information system was created at the Pelangi Sungai lilin shop. Keywords: Point Of Sale, RUP, information system, Inception, Elaboration, Contruktion Dan Transition