The KVN was built by Korea Astronomy and Space Science Institute (KASI) for achieving the main goals; a)to study the formation and death of stars with observing water (H2O), methanol (CH3OH), and silicon monoxide (SiO) masers at high resolutions, b)to investigate the structure and dynamics of our own Galaxy by conducting highly accurate astrometric VLBI observations toward the galactic radio sources, and c)to study the nature of active galactic nuclei (AGN) and their population at high frequencies. The KVN as a dedicated-VLBI network also aims to study the spectral and temporal properties of transient sources such as bursting star-forming regions, intra-day variable compact radio sources, gamma ray flaring AGNs, etc by conducting systematic multi wavelength monitoring campaigns (Kim et al. 2004, Proc. 7th Symp. EVN, 281; Lee et al. 2011, PASP, 123, 1398; Lee et al. 2014, AJ, 147, 77).