This paper presents payload estimation based on experimental friction coefficients identification. To estimate exact payload mass, dynamic mathematical model such as actuator dynamics and front linkage dynamics is derived by using Newton-Euler method. From the dynamic equation, nonlinear terms are analyzed and transformed. And a friction model is derived from the experiments with various conditions which have three states; boom joint angle, head and rod chamber pressures. It can identify friction coefficients and compensate friction forces. In addition, the accuracy of payload estimation system is verified through the field test.