The article studies democracy, justice and peace relation. Firstly, the relation between democracy and Justice, which is regarded as Judicial aspect, and then, the connection between these two and peace, is examined. Also, the views of some great philosophers, such as Aristotle, Kelsson, Rawls and Kant are introduced in this regard. In addition, the famous liberals reasoning in connection to democracy and peace are viewed and "theory of democratic peace" as a connection are also mentioned. There are many questions which are presented in this article, such as, have democratic countries not been in war till now? Are democrats more peace lover than non-democrats? And also, what other factors except democracy have basically influeufial in maintaining European peace since the Second World War. By introducing historical examples, the author has attempted to present the exact answers to these questions.