This paper reports an experimental study of Japanese traditional timber portal frame, especially focusing on a column restoring force works in combination with head tie beam and bearing block. The static lateral loading test with constant vertical force revealed that head tie beam has significant influence on restoring force. A higher level vertical force caused a compressive yield of bearing block, which resulted in a reduction of restoring force ratio. The resistance of restoring force by column rocking calculated by subtracting the resistance of girder and tie beam from total shear resistance could be expressed by the mechanical model. The ratio in strength of head tie beam was almost equal to that of restoring force.