The Korean VLBI Network is the one and only VLBI facility, employing multi frequency bands from 22 GHz to 142 GHz in the world. It consists of three 21m radio telescopes that are located in Seoul (Yonsei University), Ulsan (Ulsan University), and on Jeju Island (Tamna University). These radio telescopes altogether produce an effective spatial resolution, equivalent to that of a 500km radius. Compared to the American and European VLBI networks such as VLBA and EVN, the size of the KVN is relatively small; however, the KASI is currently developing an innovative multi-frequency-band receiver system in order to overcome this shortcoming. At this stage, it is possible to make simultaneous VLBI observations at four different frequency bands: 21.03-23.44. 41.89-44.30, 84.58-95.49, 124.0-142.0 GHz. The KVN is now testing an observation stage for a world-class and competitive VLBI research.