<p><b>OBJECTIVE</b>To observe the safe angle and depth of acupuncture at Jiuwei (CV 15) so that the reference data can be provided for the clinical safe acupuncture at the point.</p><p><b>METHODS</b>Ten healthy adults of either sex were selected. MRI was applied to scan Jiuwei (CV 15) and obtain the images. The safe angle and depth were collected for the correlative analysis with the body height, body mass, body mass index (BMI), nipple distance and the finger measurement considered.</p><p><b>RESULTS</b>There was no difference in the minimal dangerous angle of the horizontal needling to the right and the left between the male and the female. There was no difference in the dangerous depth of needling under the designed angle of needling between the male and the female. The safe depth of needling to the different directions: (16.99 +/- 2.86) mm for perpendicular needling, (22.72 +/- 5.35) mm for 45 degrees downward needling, (24.61 +/- 2.92) mm for 45 degrees upward needling, (53.47 +/- 5.72) mm for 15 degrees downward needling, (25.76 +/- 2.61) mm for 15 degrees upward needling, (24.89 +/- 4.34) mm for 45 degrees needling to the right, (21.79 +/- 3.84) mm for 45 degrees needling to the left, (51.19 +/- 2.69) mm for the needling at the minimal dangerous angle to the right, (51.86 +/- 2.59) mm for the needling at the minimal dangerous angle to the left. BMI was correlated to the minimal dangerous angle of the horizontal needling to either the right or the left, perpendicular needling, 45 degrees downward needling, 45 degrees needling to the right and 45 degrees needling to the left, as well as to the dangerous depth of needling at the minimal dangerous angle to either the right or the left. The body mass was relevant with the dangerous depth of perpendicular needling, 45 degrees downward needling and 15 degrees downward needling.</p><p><b>CONCLUSION</b>For the horizontal needling to the right or the left, the minimal dangerous angle should be determined in reference to BMI. For the angle of needling measured in advance, the needling depth is not required to be identified in light of the sex. For the perpendicular needling, 45 degrees downward needling and 15 degrees downward needling, the needling depth should be optioned in accordance with the body mass. For the perpendicular needling, 45 degrees downward needling, 45 degrees needling to the right or to the left, as well as the needling at the minimal dangerous angle to either the right or the left, the needling depth should be determined in terms of BMI.</p>