Abstract
Nagahozosashi-komisen has been widely used for the base of column joint of traditional wooden structure. But it is evaluated low comparing to hardware in now. As the result of experiment; the specification increased the number of plug or mortise, the maxim strength grew up in 1.5-1.9 times than standard, and the joint strength grew up in 3.7-4.8 times than stipulated value. Comparing the result of experiment with the theoretical formulas about the yield strength and destructive pattern, the presumption of strength and part of destruction can be approximated to the result of experiment mostly.