The　sponge　gold　was　obtained　by　using　＇breaking-removing　low　priced　metal　with　sulfuric　acid　oxidation　method-leaching　gold-extracting　gold　with　methyl　isobutyl　ketone　(MIBK)-stripping　gold＇　process.　The　statistical　methods　were　used　to　analyze　the　impact　of　different　factors　on　the　extraction　of　Au　(III)　using　MIBK　as　extractant.　The　factorial　designs　with　five　factors　and　two　levels　were　firstly　used　to　evaluate　the　relative　effects　that　might　affect　the　extraction　of　gold　from　the　waste　printed　circuit　board　with　MIBK.　The　results　show　that　the　factors　including　the　phase　ratio　of　organic　and　aqueous,　the　reaction　time　and　the　temperature,　have　significant　impacts　on　the　extraction　rate　of　gold.　The　phase　ratio　and　reaction　time　have　positive　impacts　on　the　gold　extraction,　while　temperature　has　negative　impact.　Based　on　this,　Box-Behnken　central　composite　design　combining　with　response　surface　methodology　(RSM)　was　employed　to　optimize　the　most　important　affecting　factors　of　the　extraction　rate.　The　optimum　conditions　for　the　extraction　are　the　organic　and　aqueous　phase　ratio　of　0.34,　reaction　time　of　12.4　min　and　temperature　of　28°C,　which　are　calculated　from　an　established　quadratic　equation　of　one　variable　regression　model.　Under　the　optimized　conditions,　the　gold　extraction　rate　can　reach　as　high　as　96.1%.　At　last,　the　organic　phase　is　stripped　with　solution　of　oxalic　acid　(5%)　to　get　sponge　gold.