USN and RFID, as new technologies for the realization of ubiquitous computing, are technically closely related with each other. In this paper, we propose an efficient processing method of various kinds of sensor data used in USN environment to provide efficiency from the view point of not only the convergence of USN and RFID technologies but also on cost and extensibility. Specifically, we propose a method of converting various sensor data into EPC data format which can be handled in ALE-compliant RFID middleware. By using the proposed method, existing ALE-compliant middleware based on international standard specification can easily handle not only RFID tag data but also general sensor data simultaneously without any changes in the middleware. And in addition, various types of ubiquitous application services can be implemented at a low cost and in a shorter time.