The cutting down of trees indiscriminately to meet up the basic needs of food and housing and thus destroying the ecological balance is called deforestation. For the increasing number of population, we need more schools, colleges, offices, business establishments and various sorts of furniture. So we cut down many trees. Moreover, in many parts of Bangladesh, people are to depend on wood for cooking their food. To make fire, they cut down trees. This cutting down of trees is deforestation which has many adverse effects. Deforestation disturbs our ecological balance. Animals and birds living in the forests are on the verge of extinction owing to deforestation. An inadequate number of trees causes drought and drought damages crops. When crops do not grow as we require, there happens famine. It is causing the greenhouse effect. Deforestation may cause desertification in many parts of the world which will pose a serious threat to our living. As a result of deforestation, carbon dioxide is increasing worldwide making the world warmer. It also causes the rise of sea-level and thereby floods coastal areas and farmland. Between 2000 and 2012, 2.3 million square kilometers (890,000 sq mi) of forests around the world were cut down. As a result of deforestation, only 6.2 million square kilometers (2.4 million square miles) remain of the original 16 million square kilometers (6 million square miles) of tropical rainforest that formerly covered the Earth. An area the size of a football pitch is cleared from the Amazon rainforest every minute, with 136 million acres (55 million hectares) of rainforest cleared for animal agriculture overall. More than 3.6m hectares of virgin tropical forest were lost in 2018. Deforestation exerts many adverse effects on climate, agriculture and our life. We should try to stop deforestation and plant more and more trees. To prevent deforestation, some pragmatic steps should be taken. A social movement should be launched to prevent deforestation. Social awareness can be raised regarding the adverse effects of deforestation.