Distance protection is the normal protection used for overhead transmission line. Maloperations or unwanted operation frequently occured and had caused disturbance to the sustem. The cause of these operations has to be identified. This study is mainly concerned on the factors that may led to the distance protection maloperations and was focussed on aparticular 275kV transmission line in the TNB system. Analysis were done particularly to determine whether the effects of mutuall coupling and load may have caused the unwanted operations.