Abstract: The loose part monitoring system developed for Qinshan Nuclear Power Phase II Extension Project is able to monitor three regions, which comprises ten monitoring channels and monitors the loose parts in RPV and SG. Several modern techniques are applied in the system, for instance, FPGA are adopted in sig-nal preprocessing and alarm processing, the DSP is applied in loose parts event discriminating, which includ-ing the real-time short RMS compared with floating long RMS, time delay, alarm channels check, and etc. These virtues make the system a powerful capacity of anti-misinformation. DAQ instead of tape recorder en-sures the integrality of data log. The synchronization of PXI bus meets the need of the locality analysis. The techniques of virtual instrument and database management provide an open entry for the diagnose of loose part events, and the display turns to more visual. In addition, the system had other useful functions, such as fault channels self-testing and shutting, disk space checking and software protecting as soon as power-off.