Abstract: Langmuir equation is one of the commonly used adsorption isotherm equations, there are two methods of Langmuir equation parameters estimation: linear regression method and nonlinear regression method. Based on the measured data, this paper using the IBM SPSS Statistics 24.0 software to compare the linear regression method and nonlinear regression method of Langmuir equation parameters. The results show that the linear regression method does not satisfy the minimum of the residual sum of squares of the dependent variables of Langmuir equation, rounding off for values from the irrational number to finite decimal is the cause of round-off error in the linear regression method. Because the nonlinear regression method has the characteristics of smaller residual sum of squares of the measured data, the nonlinear regression method is recommended in the Langmuir equation.