This paper shows the concept of communication, the type of communication, the communication styles, and the assertive style of communication, the techniques of assertive communication and assertive training. The word communication comes from the latin word ''communicatio'' what means statement/announcement. Through communication people state their opinions, needs and intentions. Successful communication is based on mutual balance of verbal and nonverbal messeges. Business communication is also a scientific discipline which deals with studying communication of business organization. Business communication covers communication between groups and individuals because of performing business activities.Passiveness is some peoples feature that makes them back down in front of the opportunity to say what they really mean and feel, to simply give up of satisfying their needs and to, in every way possible, try avoid conflict with others. In case of the aggressive people, urge to dominate and oppress others is stronger than urge to implementate their rights. They often use elevated tone, show anger, command, threat and insist. People with passive-aggressive style think about themselves that they are powerless and weak. It's all about camouflaged aggressiveness which we don't show open and directly, we show it indirectly, because showing aggression might have negative consequences which we don't want to deal with. In general, this communication style looks like passive, but in his core it is aggressive.People who use this communication style always have the role of victim and proudly point that out, complaining about injustice which they didn't even try to stop. Assertiveness is communication skill that acquires through the whole life. To be assertive means actively stand up for yourself and for your rights, show your needs and opinions in a direct, unambiguous and open way, considering and not threatening others with it. This kind of behaviour is helpful in every potential frustrating social contacts, when interests or needs of the other person are under a threat, when the person comes in front of the unjustified demand of the others, or simply a demand which he wants to turn down, when his rights are threatened or he finds himself in front of any kind of injustice. Assertive training all over the world became popular exactly because people understood many benefits of learning this skill. Professional leading through assertive training can get you to every important aspect of assertive communication, win the fears of social interaction and give you practical advice for training and continuously developing learned skills. Assertive training happens in two phases: the first one is systematically practicing assertiveness through advisory work, and the other one, systematically practicing assertiveness in real life situations.