Abstract: This paper describes the calibration of the newly manufactured BPMs developed for injection system upgrade in NSRL phase II project, as well as the electrical field fitting and error calculation. The antenna calibration system employs an equipment whose precision adjusted to 10m m and with vertical vacuum pipelines, and a signal processor with 1m m of resolution and working in RF of NSRL ring. The fitting error of the electric field is presented. With the calibrating system and processing method which has a system error about ± 15m m and the precision of 1m m, we have completed the calibration and quality checking of the developed equipment. Due t o the vertically fixed beam pipe and the antenna's movement to simulate beam orb it deviation, as well as the adoption of the RF CW to simulate