Negotiation is applied to many fields, which are included in politics, business and even in daily life. An outstanding negotiator is not congenital, but it can be trained to be an excellent one. The type of negotiator what the person will be is affected by his personality. Negotiation is affected by many factors, and we will discuss the personality in this research. We focus on Machiavellianism and self-monitoring which are the two major variables in this research. And we use Ethical Decision Making Model to establish the hypothesis in this research. The questionnaire survey is the main method to collect the data, and we investigate the relationship among negotiator¡¦s p personality, attitude toward negotiation tactics and negotiation intention by descriptive statistics, T-test, Analysis of Variance and Regression Analysis. The results are follows: (1) Different backgrounds significantly influence the ethical attitude toward negotiation tactics, for example, the negotiator¡¦s sex and level of education. (2) Machiavellianism significantly influence s the ethical attitude toward negotiation tactics, for example, the negotiators have higher level of Machiavellianism and their ethic attitudes are weaker in ¡§salami-tactics¡¨ , ¡§shock them with your opening offer¡¨ and ¡§advance man¡¨. (3) The degree of self-monitoring of the negotiators significantly influences the relationship between ethical attitude toward negotiation and negotiation intention. Keywords: Negotiation tactic, ethical decision making, Machiavellianism, self-monitoring.