A variety of devices and ubiquitous computing systems such as RFID (Radio Frequency Identification) generate and exchange significant events during their execution. In this paper, compared to most existing RFID framework, We provide a framework of RFID system based on Complex Event Processing which aims at providing a scalable solution for gathering, filtering, and providing clean RFID data. We design a complex event detection algorithm of performing Complex Event Processing directly over unreliable RFID event streams by incorporating cleansing requirements into complex event specifications. We explain how raw RFID events can make business process data accessible for process mining. The results of this research can be widely used for RFID events analysis in various areas such as logistics and manufacturing systems.