PRPRS(Patent-Reel munber Parellel Retrieval System)is a practical system.After you input a patent number of a country or an organization,it will timely output the number of the reel in which the original is located.The system is successfully developed with C language under DOS on PC.Its interface is very user-friendly,and its response time is fewer than 7 seconds.The database which supports the system has more than one million records,and it can expanded continuosly.Although the compress technique is used to set up the database,the record is logically put in order,therefore the retrieval speed is raised.