More recently, RFID (Radio Frequency Identification) systems have begun to find greater use in various industrial fields. The use of RFID system in these application domains has been promoted by efforts to develop the RFID tags which are low in cost, small in size, and high in performance. The RFID applications enable the real-time capture and update of RFID tag information, while simultaneously allowing business process change through real-time alerting and alarms. These be developed to monitor person or objects with RFID tags in a place and to provide visibility and traceability of the seamless flows of RFID tags. In this time, the RFID readers should be placed in diverse locations, the RFID flows between these readers can be tested based on various scenarios. However, due to the high cost of RFID readers, it may be difficult to prepare the similar environment equipped with RFID read/write devices. In this paper, we propose a simulator to allow RFID application testing without installing physical devices. It can model the RFID deployment environment, place various RFID readers and sensors on this model, and move the RFID tags through the business processes. This simulator can improve the software development productivity by accurately testing RFID middleware and applications. In addition, when data security cannot be ensured by any fault, it can decide where the problem is occurred between RFID hardware and middleware.