In this paper, we study the challenging problem ofoptimizing gateway placement for throughput in Wireless MeshNetworks and propose a novel algorithm based on Ant ColonyOptimization (ACO) for it. The ACO algorithm is originatedfrom ant behavior in the food searching based on pheromone.We generate the locations of gateway randomly andindependently then calculate the probability and pheromonevalues of ants will choose to go from current gateway i to nextclient j. After each iteration, the pheromone values are updatedby all the number of ants that have reached to the destinationsuccessfully and found a optimal solution. Numerical resultsshow that the proposed algorithm has achieved much betterthan previous studies