Abstract: An improved artificial bee colony (IABC) optimization algorithm is presented for assignment problem.In consideration of the solution's discreteness, this algorithm gives a discrete coding method for the food source position.The algorithm adopts neighborhood shift to produce a candidate food position, which can ensure the solution feasible and increase the diversity of food sources.The actual calculation shows that the IABC algorithm can accelerate the convergence process obviously and improve the precision compared with the original artificial bee colony (ABC) algorithm, and this method is also superior to other particle swarm optimization (PSO) algorithms.The principle of this algorithm is simple and its application is flexible and easy.It is a new algorithm for assignment problem and it presents a new vision for other combinatorial optimization problems.