We performed molecular dynamics (MD) simulation of 9 million pairs of NaCl ions with the Ewald summation and obtained a calculation speed of 1.34 Tflops. In this calculation we used a special-purpose computer, MDM, which we are developing for the calculations of the Coulomb and van der Waals forces. The MDM enabled us to perform large scale MD simulations without truncating the Coulomb force. It is composed of WINE-2, MDGRAPE-2 and a host computer. WINE-2 accelerates the calculation for wavenumber-space part of the Coulomb force, while MDGRAPE-2 accelerates the calculation for real-space part of the Coulomb and van der Waals forces. The host computer performs other calculations. We performed MD simulation with the early version of the MDM system: 45 Tflops of WINE-2 and 1 Tflops of MDGRAPE-2. The peak performance of the final MDM system will reach 75 Tflops in total by the end of the year 2000.