The direct integration method to enhance the calculation accuracy of electromagnetic responses for current dipole source over layered earth is discussed. In the method Hankel integration in frequency domain is divided into several partial ones and are evaluated with the method which combines Gauss quadrature rule and continued fraction. The utility of continuous fraction can speed up the convergence greatly. Using the method the electromagnetic responses for half-space and two-layered earth models are tested. Compared with traditional numerical filter method, the result shows that the direct integration technique can improve the frequency response simulation accuracy of electromagnetic soundings for 1D earth, and gives calculating base of obtaining the very late time electromagonetic responses with high accuracy.