Abstract: In order to simulating the formation of coronal surges, the characteristics ofmagnetic reconnection caused by the resistive tearing instability in bipole-monopolemagnetic field are studied numerically by using a two-dimensional, time-dependent,compressible magnetohydrodynamic simulation. The results show that the magneticlines of the bipole and monopole fields will reconnect directly and the evolution ofmagnetic field leads to a whip configuration under a magnetostatic basic state whichincludes three regions ── a bipole, a current sheet and a monopole. The upwardplasmoid supported by bended magnetic field diffuses and falls back to solar surfaceafter reaching its maximum height. The upward velocity of plasmoid reaches 0.10v_A(v_A is Alfven velocity in bipole magnetic field). The simulated result confirms thatthe formation of coronal surges may be related closely to magnetic reconnection inbipole-monopole magnetic field.