Trees are closely bound up with human's existence. Many countries in the world are paying more and more attention to tree planting and forestation. March 12 is the Arbor Day in China, which is settled on the Sixth Session of the Fifth Standing Committee of the National People's Congress in February 1979. In December 1981, the Resolution of Developing Obligatory Tree Planting in the Whole Nation was adopted at the Fourth Session of the Fifth National People's Congress. The next year, the State Council decreed the Implement Measures on Obligatory Tree Planting. In the days before and after the Arbor Day, people gather together and plant trees. After 20 years' effort, tree planting has become a quite popular activity in China, and has achieved great success.