The objective of this study was to identify and to interpret the word nam ja mok kai(南子木蓋) in Keirim Yusa(鷄林類事). Comparative linguistic analytical approaches ware employed for this research. Results and findings, of this study can be summarized as follows: It was fond that similar words to jamok kai(子木蓋) of Koryo were in Mongolic, Manchuric as well as in Hebrew. Thus, the word nam ja mok kai(南子木蓋) is not reversed word of nam mok ja kai(南子木蓋). The word jamokkai and the meaning of it were derived from Hebrew.