AbstractThe vertical motions of 11 control points in the Northern part of Israel, Haifa North-East, were studied for a period of 1 full year (October 1988 to September 1989). In Israel control points on high tension poles are used as levelling bench marks. The purpose of this research was to determine the reliability of these control points as bench marks. A precise levelling network was established consisting of four levelling loops with the network being measured with an Zeiss Ni2 level equipped with a parallel plate micrometer. The total distance of the levelling network for a single run was 8.4 km. Four sessions were observed at 3.5 month intervals. As a result of the analysis, it was observed that the control points move in a cyclic manner with a nearly annual period.