Traditional pelvimetry for a pregnant women is mainly relied on a ruler or estimation based on the vaginal touch, which results a very high measuring error. A new pelvimetry based on electromagnetic tracker is proposed in this paper , and a measure system has been developed . It’s a non-invasive method to measure key parameters of a pelvis because of the character of high accuracy, without line-of-sight restrictions and non-radiation of electromagnetic tracking technology. Its precise measuring data can well fulfill clinical pelvimetry needs, and be helpful for a physician to make decisions to go on a vaginal delivery or not during a labor.