Śamatha practice is the foundation of all moral practices. Once one achieves single-pointed states of serenity through Śamatha, he or she can proceed further to practice Vipaśyanā, disenchant with cyclic existence, and comprehend emptiness. In this article, we start from unearthing the contents related to Śamatha embedded in the foundation before paths, the path shared with persons of small capacity, the path shared with persons of medium capacity, the path for persons of great capacity in “Lamrim Chenmo”, and elucidate the reason why Tsong-Kha-Pa explained Śamatha after the six perfections and the four ways to gather disciples in the path for persons of great capacity. The main subject is to investigate the preparation, meditative posture, and objects of meditation for Śamatha practice, as well as the stages by means of the eight antidotes which eliminate the five faults in “Lamrim Chenmo”, so as to develop nine mental stages, dispel misconceptions, and turn into the foundation of Vipaśyanā practice. These materials shall be compared with the meditation methods given in “Yogācārabhūmi-śāstra”, “Sandhinirmocana Sūtra”, “Separation of the Middle from the Extremes” (Madhyānta-vibhāga), and “Mahāsatipaṭṭhāna Sutta”, in order to acquire complete and correct teachings for Śamatha practice. The biography of the author, Tsong-Kha-Pa, including how he practiced and propagated Buddhist teachings, will be appendixed at the end.