The　partner　selection　problem　with　a　due　date　constraint　in　virtual　enterprises　is　proved　to　be　NP-completeness　problem.　So　it　cannot　have　any　polynomial　time　solution　algorithm　at　present.　Nonlinear　integer　programming　model　for　the　problem　is　established.　The　objective　function　and　constraint　function　of　the　model　have　monotonicity　properties.　Based　on　the　above　observations,　a　Branch-and-Bound　algorithm　is　constructed　to　solve　the　problem.　Numerical　experiments　show　that　the　algorithm　is　effective.　©　2005　IEEE.