Analyzing reasons for system errors in measurement of earth resistivity, several methods to remove the errors are proposed.It's believed that the system errors are influenced by the accuracy of setting coefficient K, sampling resistor R_I and measured ΔV and V_RI.The R_I with high precision and stability is chosen, the "suspending" measurement is applied and the same A/D converter with wide dynamic range and high linearity is used to measure ΔV and V_RI in developed terrameter by the authors for decrease of the system errors.At last, effect of the "suspending" measurement is verified by test in laboratory.