Using the KSP VLBI network, we are routinely monitoring a crustal deformation around south Kanto area, Japan. Though all the stations lie in the same plate, we could observe a significant crustal deformation. In particular, the two baseline lengths, Koganei-Miura and Koganei-Tateyama, show a remarkable decrease: -12mm/yr and -16mm/yr, respectively. Moreover, the strain analysis of the triangle formed by Koganei, Kashima and Tateyama indicate a compression whose principal strain rate is 0.17 microstrain/yr along the axis almost toward north-south direction. Similar amplitude and direction are independently reported by Kato et al.(1998), whose estimate is based upon GSI's nation-wide GPS array. The direction of the principal compression axis is, however, counter-intuitive, on account of the velocity of Philippine Sea plate relative to North-American plate. Geophysical interpretation is going to be presented.