A method of controlling hand over that reliably performs SHO even when there exists discrepancy between a range of a cell or sector and a range in which communication is possible. A reference value, which is compared with a received level of a perch channel signal for judging timing of starting and ending SHO, is corrected by using a correction value prepared for each combination of an SHO source cell and an SHO destination cell. The reference value is corrected such that SHO is started when the mobile station 10 arrives at a range in which the mobile station 10 can communicate with a base station 21 that covers the SHO destination candidate cell, and the hand over is ended when the mobile station 10 comes out of a range in which the mobile station 10 can communicate with a base station that covers the SHO source cell.