Attitude and behaviour are the ones that determine the styles of approaching a negotiation. Our moods make us feel better and more comfortable in some situations and not at all at our ease in other situations. We are aware of some of our moods, we discover others on the way, and there are some whose existence we never discover. In our relationships we seek some situations and we run away from others. The same thing happen in negotiation. We seek styles that we like and and we react difficult and usually inadequate to those which are not appealing to us. When others try to manipulate us or they subject us to some diversion or intimidation techniques, this is what they are after: to lead us to uncomfortable situations from which we are trying to escape. And in order for us to escape, we will have the tendency to cease only to leave the place. As professionals we have to know to deal efficiently with these kind of situations. There are many ways to classify the human behaviour in negotiation. One of them is highlighting diferences regarding two points. Openness and directivity. From the openness point of view some people are more open, more communicative, more social than others who are close and not social. The second way divides people in direct and indirect. When communicating, some people express directly and face to face what they have to say, others need beyond the word meanings, hints and diplomacy to express themselves. Another way of diferentiate is that which divides people in competitive and cooperative. The competitive ones lead the relationships wiht agresivity. In a negotiation they are more preocupied with the material results. For them, negotiation means confrontation. What they win, the others loose. And the other way around. Generally they ignore the relationship. The cooperative ones are more focused on the relationship, they are more orientated to cooperation, sometimes with loss regarding the material result. For them, a positive result in a negotiation is to maintain a good relationship. In my opinion, this is the most relevant way of classifying the human behaviours regarding the negotiation. It defines the negotiation styles known in the professional literature as win-win – cooperative and win-lose – competitive. Any behaviour has at its base feelings which generate it. We laugh because we are happy or because we are feeling well, we cry because we are sad we slam the door because we are angry, we defend ourselves because we are afraid, we collaborate with someone because we have trust. Feelings are the ones which explain our behavior. And in order to understand and modify the behaviours of our partners in a negotiation, we have to understand their feelings. Greed, vanity, frustration, fear, ambition, courage, trust, faith are the most common feelings which manifest themselves in a negotiation. They are behind behaviors and we must be able to identify them. On the other side though, professionals don’t have feelings. It’s a way of saying. They also have feelings, but they are trained not to manifest them. They know to do things in such way so that their own feelings will not stand in the way of achieving their goals and moreover they are trained to take advantage of the feelings coming from other. Professionalism can be achieved by training an/or by experience. So, each time we interact with a professional and we manifest ourselves, we become vulnerable because we give him information about ourselves. And they will use it for their advantage.