Goal-setting theory has been broadly used in management to motivate employees.The relationship between goal difficulty and goal specificity with task performance is important topic in goal-setting research.Through an experiment study,the main purpose of this paper is to explore whether specific goals has significant effect on performance and what on earth the relationship between goal difficulty and performance is .The result reveals that in comparison with non-specific goal.specific goal has no significant effect on performance;goal difficulty has positive correlation with task performance;the performance waves up along with the goal difficulty instead of arching down.