Abstract: The uniaxial tensile test and small punch test of X80 pipeline steel were carried out. The influence of specimen thickness on the elastic modulus, yield load and maximum load obtained by small punch test was studied by correlating the two test results. The empirical formulas of yield strength and ultimate tensile strength with thickness as independent for X80 pipeline steel were given. The results show that the yield load and maximum load obtained by the small punch test had a linear relationship with the square of specimen thickness. The yield strength and tensile strength calculated from the established empirical formulas were less affected by the thickness, and the maximum relative errors from the uniaxial tensile test results were 11.2% and 12.3%, respectively.