A series of compressive loading tests was conducted to clarify the effect of spacing of ties and cross ties on the lateral confinement of concrete. It is found that the peak stress and the strain at the peak stress of confined concrete decrease and the slope of the falling branch increases as the tie spacing increases. This is because the increase of tie spacing results in a decrease of confinement stress of concrete between ties. An empirical formulation for the peak stress, the strain at the peak stress and the slope of the falling branch was developed taking account of the tie spacing.