Electronic Product Code (EPC) Track&Trace service is a method to realize real time visibility across a supply chain. EPC Track&Trace service gathers specific EPC information such as shipment time and place of the products tagged with RFID from each EPC information system (EPCIS). However, it takes a lot of time to retrieve all the EPC information from each EPCIS because of their distributed nature (world wide). In order to reduce the query response time from EPCISs, this paper proposes Proxy based EPC Track&Trace service architecture under EPCIS Phase2 that introduces a proxy layer inside the EPCIS. EPCIS that requests EPC information can receive the data locally by connecting to the proxy layer without connecting to the remote EPCIS each time, which reduces the query response time. This paper also proposes a data structure scheme and a synchronization method between the EPCIS and the proxy layer under the EPCIS Phase2 working draft. These schemes improve the performance in data query response time and data reusability.