Time-series observations were carried out using a 155mm refractor and a 2k×3k CCD camera at Bohyunsan Optical Astronomy Observatory. We found 38 new variable stars in the 2.3°×2.4° region around the Cepheid variable TU Cas: 22 eclipsing binary stars, 11 δ Scuti type stars and an RR Lyrae star, and 4 unclassified variables.