Leaching test was conducted according to AMPA M11 87 standard. Pinus massoniana and Eucalyptus urophylla were treated with ammoniacal copper quat type B （ACQ B）, copper citrate （CC） and chromated copper arsente type C （CCA C）. Leachability determination results showed that the leaching rate was less than 2.5% for the wood treated with ACQ B at the retention of 3.0～6.0 kg/m 3. The anti leachablitity of wood treated with ACQ B was better than that treated with CC, because the leaching rate of wood treated with ACQ B was lower than that treated with CC at almost same copper retention level （as copper oxide）. ACQ B was a potential wood preservative for plantation wood used in the ground field such as agricultural and building wood.