The aim of this paper is to trace back both to the introduction of the green tea into Japan and the birth of tea culture. How was the green tea brought to our country, Japan? There are some opinions about this question. One of them is the view that the tea was introduced by the excellent priests who studied in China in the early Heian era and that in Kamakura era the tea had a close connection with Buddhism. The priests drank tea in order to be in high spirits during their religious mortifications. The priest Eisai described in his famous book "Kissa Youjouki" about the medicinal effects and the stimulant power of the tea. Then only the privileged people could enjoy drinking tea during some five hundred years from its introduction. In Nambokucho era 'Tocha play', that is a kind of competition to guess what kind of tea the man is drinking, became popular. And the custom of drinking tea began to spread widely even among the common people. From the middle of Muromachi era to the Sengoku era, Murata Juko and Takeno Joou established the base of tea ceremony and then in Azuchi Momoyama era, Senno Rikyu came out to complete the essence of what is called the spirit of tea ceremony of Japan herself. Thus this paper describes plainly the history of tea culture by referring to thirteen pieces of historical sources.