Summary: Due to the increase in the number of users on the web, it becomes easier to exchange and analyze their data. This system makes it possible to detect the trend of terrorism on the social web, mainly Twitter. Jihadist groups like ISIS spread propaganda online using various forms of social media such as Twitter and YouTube. One of the most common methods of stopping these groups is to suspend (temporarily block) accounts spreading propaganda when they are discovered. However, this method requires human analysts to manually scan and analyze a massive amount of social media information. This system makes it possible to do this automatically (detect radical content disseminated by jihadist groups) on Twitter. The main idea of ​​this system is to predict whether a person tends to be terrorist or not. Machine learning (ML) and natural language processing (NLP) approaches are used to obtain a preliminary determination of terrorism tendency by analyzing public tweets posted on Twitter. In this system, three machine learning algorithms are used (Support Vector Machine (SVM), Naive Bays and AdaBoost), the accuracy of the three algorithms is compared to decide which one is better when using our datasets. In conclusion, our system aims to reduce the increase in the spread of terrorism on social networks (Twitter). Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an original essay. Finally, we will discuss how our system can be modified to work on other behaviors and contribute in other ways to research on human behavior. Keywords: natural language processing, machine learning, behavior analysis, social media analysis, Twitter, Facebook, YouTube.I. INTRODUCTION SINCE the late 1980s, the Internet has become a center of communication between all people in the world and more and more people around the world are taking advantage of the benefits that the Internet offers. Many technologies have been developed to reconnect people across continents. In 2014, there were more than 4 billion Internet users and this number continues to grow [26]. Internet technology has many advantages, including the increasing ease of sharing and rapid access to information and ideas. Businesses, consumers, organizations and governments have started using the Internet as a means of communicating with each other. It has also created an ideal atmosphere for various terrorist organizations to spread radical information (in a big way, more importantly than ever before) that supports their own twisted causes. Federal officials say the Islamic State (ISIS) and other similar extremist organizations are currently attempting to use social media and the Internet to recruit and radicalize dissected citizens on a daily basis. It is therefore crucial to detect such groups by scanning and then analyzing data flows from social networks. There are many terrorist organizations in the world and the media reports almost daily that terrorists are attacking in different parts of the world. According to [20], terrorism has the following characteristics: It involves violent or dangerous acts to human life that violate the law (whether federal or state). Seems intended to intimidate a civilian population. Intends to violate government policies through intimidation or coercion. They.