The research project ’s purpose is to survey the background Khowledge regarding a new security in the issue of terrorism, There are five chapters to this project. Chapter one addresses the some of the historical and modern periods of terrorism since the first century until now ,with a central theme is deeply in the human experience. Chapter two gives a select of straightforward definition which help understandingand and discussion. This is followed by excerpts from the varied of defining terrorism from both a sampling of formal and informal definitions. Chapter three explore the cause of terrorism in detail both internal and external environment factors and especially a motivation in a psychology and chapter four is designed to be a content of characteristics terrorism in the past and present in a comparative aspect , typologies of terrorism , objectives of terrorism and targets of terrorism. The last, chapter five gives the growth and varieties of terrorist groups in detail. The bombings in Bali on 12 October 2002 has shown that the Jamaah Islamiyah (JI), Islamist terrorist organization, has emerged as the biggest threat to Southeast Asian security. JI, which has Indonesian origins, seeks to establish a Daulah Islamiyah Nusantara, or an archipelagic Islamic Southeast Asian state incorporating Indonesia, Malaysia, the southern Philippines, Brunei, Singapore, and southern Thailand, Cambodia, Australia included. Despite the arrest of Abu Bakar Ba’asyir and Hambali, JI’s key figures, the group remains active and dangerous. The study aims to gain a deeper understanding of JI’s origin, structure and network in the region. It also focus on the response of the Indonesia, Malaysia and Singapore which generally have varied with the intensity of their concerns about the threat to their own stability and domestic politics. The paper is divided into three chapters. The Chapter One outlines the history and ideological development of JI from its origins in the Indonesia – based ‘Darul Islam’ movement to its transition as international terrorist group and network of Al – Qa’ida in Southeast Asia. The Chapter Two surveys JI’s organization including recruitment and financial structure and its ties with Al – Qa’ida and other radical militant groups in the region. This chapter also looks more closely at two of JI’s major operations, the Operation JIBRIL and Bali Bombings, to examine its capability in planning and field operating. The last Chapter looks ahead to examine how the Indonesia, Malaysia and Singapore government response the terror of JI and protect its people from the threat of terrorism. In the past and particularly in the aftermath of September 11, events, some Western media and scholars have been trying to portrayed Islam as a faith advocating hatred, intolerance and spread of terror. But this negative image of Islam is, however, far from the truth. Indeed Islam is the message of peace, justice, sanctity of human life, tolerance and co-existence with minorities. The vast majority of Muslims in the World, like the believers of other religions, are family and community oriented who wish to live in peace and harmony rather than in warfare and in the state of terror. However, terrorism is an old age phenomenon and has always existed in its various forms and types, in every part of the World. It has no religion. It is a sinful phenomenon involving misguided perpetrators of every faith. While the terrorist must be condemned and hunted down, it is even more important to deal with terrorism. In fact, terrorism must be studied objectively and open mindedly to diagnose the disease and eradicate it from the World In the past and particularly in the aftermath of September 11, events, some Western media and scholars have been trying to portrayed Islam as a faith advocating hatred, intolerance and spread of terror. But this negative image of Islam is, however, far from the truth. Indeed Islam is the message of peace, justice, sanctity of human life, tolerance and co-existence with minorities. The vast majority of Muslims in the World, like the believers of other religions, are family and community oriented who wish to live in peace and harmony rather than in warfare and in the state of terror. However, terrorism is an old age phenomenon and has always existed in its various forms and types, in every part of the World. It has no religion. It is a sinful phenomenon involving misguided perpetrators of every faith. While the terrorist must be condemned and hunted down, it is even more important to deal with terrorism. In fact, terrorism must be studied objectively and open mindedly to diagnose the disease and eradicate it from the World