Finnish modern designers would like to follow the principle of blending in nature. This paper demonstrate the close relationship between design of Finnish outdoor chair and nature in three parts: the materials of outdoor chair come from nature; the usage of outdoor chair is harmonious with nature; a good sense of humor in outdoor chair is put in nature, and analyzed Finnish national aesthetic spirit and design idea meanwhile. Conclusion is that Finnish outdoor chair expresses the Finn's belongingness of nature. Designers fulfill the design principle of Alvar Aalto's Organic Functionalism, and pay close attention to respecting both nature and human.