WHAT IS THE BIGGEST CHALLENGE TO BIODIVERSITY CONSERVATION. Conservation of biodiversity and its use in sustainable development have been impeded by many obstacles. The need to mainstream the conservation and sustainable use of biological resources across all sectors of the national economy, the society and the policy-making framework is a complex challenge at the heart of the Convention on Biological Diversity (CBD). Major challenges to implementing the conservation of biodiversity and its use in sustainable development are many. But there are some major thing that we will discuss about: Exotic species; Government policies; Habitat degradation and Population growth and increasing demand for biological resources. On the overall, each challenge has a different problem and special issue that hard to face or solve but the biggest challenge to biodiversity conservation is absolutely coming from human and it is “Population growth and increasing demand for biological resources” As we use biodiversity to meet our demand under the above points, population increase in the world stands as a major problem because it increases consumption creating pressure for using bioresources more and more. The world is losing its tropical forests at the alarming rate of almost 42 million acres per year. The largest areas of forest loss occurred in Latin America, followed by Africa. However, when deforestation is measured as a percentage of the remaining forest, the most losses happen to have occurred in Asia. At the current rate tropical forest will be gone within 115 years. Population in the world is currently (2018-2019) growing at a rate of around 1.07% per. The current average population increase is estimated at 82 million people per year. The demand for food to feed the world's increasing populations will continue to put pressure on forest lands. Nearly 30 tree species in hill forest, 20 species in plain land forest and 30 species in the littoral forests used to be commercially exploited. In the study the impact of population growth and increase, demographic statement of the local people involved, family affairs and tradition, and their education systems were taken under consideration. The local people are culturally habituated to go inside the forest every morning and have some wood or undergrowth plants cut for selling in the market nearby. Source: http://www.dailymirror.lk/article/Conservation-of-Biodiversity-for-Sustainable-Development-inSri-Lanka-150222.html https://www.sciencedirect.com