We propose ConArg, a tool based on Constraint Programming, to model and solve various problems related to the Argumentation research field. Constraint Satisfaction Problems (CSPs) offer a wide number of efficient techniques (as inference and search algorithms) that can tackle the complexity in finding all the possible Dung's conflict-free, admissible, complete, stable, preferred and grounded extensions in Argumentation Frameworks. Moreover, we can use the tool to solve some computationally hard problems presented in [1]. To implement ConArg, we have used JaCoP, a Java library which provides the user with a Finite Domain Constraint Programming paradigm, to model and solve these two problems. ConArg is able to randomly generate two different kinds of small-world networks in order to find Dung's extensions on such interaction graphs. We present the main features of ConArg and the reported performance in time.