The traditional pull-off method to measure the surface tension coefficient of liquid is improved in this work，where a series of metal rings with different cross-sectional areas were designed and employed． The relationship in-between the cross-sectional area of the metal ring and the surface tension coefficient of the liquid was investigated．The experimental results show that the larger the cross-sectional area of the ring is，the larger the measured tension coefficient will be，and the relationship in-between which is approximately linear．