Abstract: The spallation target of ADS was studied using LAHET and MCNP code. Since the basic physical properties of the target material vary according to the beam conditions and target geometry, the effects of beam condition and target geometry on the target properties were checked firstly. Then the simulating calculation of the lead target of 1.2 m length and 0.6 m in diameter bombarded with 1.0 GeV proton beam was (carried) out. The neutron production and leakage, energy deposition in the target were studied. The simulation results agree very well with the previous theoretical and experimental results. The calculations show that the energy of the incident proton and the target geometry make an important impact on the neutron production and leakage. For the given liquid Pb target, the neutron production and leakage are high and the leakage neutron spectrum shows to be good in the reactor. But energy deposition in the target is so inhomogeneous that it may be a challenge to the cooling of the target.