Jakarta - "Good morning, hello…hey..hey…hello…” greetings from WALHI National staffs to students of Semut-Semut The Natural School (Elementary School), they replied with enthusiasm, this activity is part of educational campaign on environmental study for students conducted by WALHI National in schools. To study cheerfully would be perfect to describe the learning atmosphere when the representative of WALHI National came as Guest Teacher at Semut-Semut The Natural School during the Environmental Subject which was the part of World Environment Day celebration celebrated every 5^th of June. During the lesson, the students were introduced to the function of forest for the earth and Indonesia’s role as one of the countries having the most forest in the world to protect its forests from any damages. The first material was to introduce the students to forests in Indonesia, Melva Harahap from Organization Strengthen Department of WALHI explained, “that Indonesia is known for one of the hugest forest in the world, not only the place for trees to grow, but also a home for fauna and flora with all diversity in their species, including human.” “Forest produces millions of oxygen needed by all the living creatures. Unfortunately, day by day, the condition of forests in Indonesia is getting worse. Forests in Indonesia is decreasing caused by the threat of palm oil plantation industry, paper and paper pulp industry, mining industry, and many infrastructure developments,” added Melva to 450 elementary students located in Depok. In another session, the students were asked to know better about WALHI and what are the activities that WALHI does. Last session was a movie screening about environment titled “Recover Indonesia” and "Climate Justice: Save Peat Land Ecosystem." The students watched with full attention. Before ending the learning sessions, the students gave donation to WALHI through Green Savings worth IDR 3,969,000. The students of 1^st – 6^th grade collected some of their money for the donation; this helps WALHI so much in its effort to save environment in Indonesia. Let’s care about our forest since young age.