Time delay in bilateral control system seriously deteriorates the performance and stability. A time delay compensation method based on the concept of network disturbance (ND) and communication disturbance obsrver (CDOB) has been proposed and the validity has been verified so far. Time delay compensation by CDOB improves the "Operationality" of master robot but simultaneously deteriorates "Reproducibility" of environmental impedance. This paper proposes scaling down compensation value(SDCV) of CDOB only in contact motion with an environment to realize both good reproducibility and operationality. Reproducibility is improved in all frequency range by scaling down compensation value from 0 to 1.0. The validity of proposal is verified by experimental results.