1. A computer system for analyzing jitter of signals, comprising: a jitter analyzing unit for obtaining a signal file, identifying a type of the signal file, defining a jitter analysis mode, obtaining a differential signal from the signal file, rebuilding an ideal clock according to the differential signal, calculating and analyzing the jitter of the differential signal based on the rebuilt ideal clock, and generating and outputting a jitter analysis wave according to the defined jitter analysis mode; and a storage for storing the signal file and source codes of applications executable by the jitter analyzing unit.