Nowadays, many countries around the world are recognizing that tourism is an important driving factor for the economy development by promoting more national revenue, boosting Gross Domestic Product (GDP), increasing Employment Opportunity, improving living standard, maintaining trade balance, and reducing poverty. Each year tourism brings billions of U.S. dollar revenue to the economy of numerous countries including Cambodia. Today I will rest up three main points that tourism is important for national economic development.The first one is generating more national revenue. Tourism is a significant source of revenue for any nation around the world because tourists who come to explore new places and experience unique activities bring in money that can boost the national economy. This spending occurs in a variety of ways like expensing on transportation, accommodation, food consumption and other services such as guide service rental and traveling ticket etc. As a result, businesses of all types and sizes have the potential to earn more income and this in flow of money can benefit not only business owners but also employees who will have more money to spend within the national economy.The second one is about job creation and opportunity. Tourism is also an important source of employment for residents. The growth of the tourism industry means more job creation and opportunities for people in various fields such as hospitality, transportation, tour operators, tour guides, handicrafts, and retail businesses. As more tourists come to visit, new businesses arise, and existing businesses expand, which provide new job opportunities to more people that lead to reduced unemployment rates and improve the living standards of the people in the nation.The last one is about attracting more investment and international relations. When a nation is full of peace, it will attract more tourists to visit and entertain themselves and it needs to develop a better infrastructure like building more roads, hotels, restaurants, supermarkets, and entertainment parks. With the peace, stable and security environment, that nation can attract more both local and foreign investors to create new businesses and services as above. Tourism also promotes relationships between nations by encouraging the flow of people from one nation to another nation in finding and experiencing new cultures and customs; moreover, they also could find their business partners.