Ship Positioning’s Thruster Allocation is a nonlinear programming problem with nonlinear equality and inequality. Morgan's direct thruster allocation method is simple and allocation's speed is quick. And Sequential Quadratic Programming, evolutionary algorithm is used to solve more complex performance index and constrains, however, load balance is not considered. In this paper, performance index is improved considering load balance. And evolutionary algorithm is used to solve the problem. Results show that search time is long. In the future, heuristic based on solved problem operator should be used to decrease time of evolutionary algorithm. For example, setting forbidden operator to eliminate unfeasible solutions. Sequential Quadratic Programming could be used to solve the problem presented in this paper with improved performance index.