Objectives : To investigate the meaning and the importance of needling or moxibustion- prohibited acupoints in Chimgugapeulgyeong(鍼灸甲乙經). Methods : We found needling or moxibustion-prohibited acupoints in Chimgugapeulgyeong, then investigated the causes of the prohibitions from the various literatures and the anatomical structures near the acupoints. Results : In Chimgugapeulgyeong, the needling and moxibustion-prohibited points were ST9, ST17, ST32, CV5, and CV15. The needling-prohibited points were LU2, LI13, ST12, BL56, KI2, KI7, TE8, TE19, GB3, CV8, GV24, and jwagak(左角). The moxibustion-prohibited points were LU3, LU8, ST1, ST7, ST8, ST30, ST33, BL5, BL6, BL15, BL30, TE18, TE21, TE23, GB22, GB33, GB42, GV6, GV15, GV16, GV17 and GV25. The major cause of developing prohibited needling or moxibustion was due to the possibility to damage vessels or organs near them; other causes were side effects brought by applying wrong stimulating method or inducing women sterilized. Conclusions : The prohibition of needling or moxibustion on the points found in Chimgugapeulgyeong had acceptable causes. Therefore the techniques of needling or moxibustion on the acupoint should be performed with care.