Abstract：This paper builds an optimallogistics node layout model with considering the land constraints and scale economy of freight based on the analysis of connotation of logistics node layout and doescomputational analysis to the model by SGA and numerical example simulation in MATLAB, the analysis of the example shows that the algorithm can Search tothe globaloptimal solution of the problem quickly and has high excellence rate. It is an effectivealgorithm to resolve problem ofoptimization of the Logistics node layout model which takes scale effect into consideration.
IndexTerms -Logistics node；layout model；scale economy of freight；Simulated annealing Genetic Algorithm（SGA）

 Ⅰ.INTRODUCTION

Logisticsnode includes three different levels: logisticsbase, logistics center, and distribution Center. It is the keysites to organize logistics operations, to complete logistics services, and toprovide logistics services. It plays the role of dispatch command andinformation center in logistics network. Optimization of the Logistics nodelayout is complex combination of many factors problem with decision-makingnature. Good regional logistics node layout can reduce the cost of regionallogistics. A large amount of research were done in the logistics node layout athome and abroad, including the following content: Classic location model、Location combined with inventory control network design model、Facility Location combined with Vehicle approach problem and Hub networkdesign, etc. However, factors of land constraints and scale economy oflogistics node are rarely considered in the above-mentioned research .Thispaper takesthe land constraintsand scale economy of logistics node into consideration and makes researchon optimization of the Logistics node layoutof a region based on theabove-mentioned research. Bi-level ProgrammingModel and corresponding algorithm are set up in this paper.