Thirty environmental enthusiasts including our school principal, parents, teachers and students attended a pro-environment activity called Tung Wah Tree Planting Day 2012 in the morning on 5 May 2012(Saturday) at Ma Tso Lung. All participants took part in the activity eagerly despite the unfavourable weather condition that day. Arriving at a closed landfill called Ma Tso Lung Landfill; we were guided to plant seedlings on a slope of the landfill. Planting trees is an easy and effective way to beautify the environment; provide shade in summer and wind protection in winter; and enhance bio-diversity of the natural environment at the same time. Before the activity, five senior students had been nominated as tree planting ambassadors and attended a training workshop. They gained the knowledge of landfill design and the skill of tree planting on a slope in the workshop. They were responsible for guiding the participants to plant seedlings on the landfill on the Tree Planting Day.