This paper is the supplementary explanation to the first chapter - The benefits of bodhicitta - of the authar's The Chinese Translation and Commentary of Bodhicaryavatara. The contents are mainly based on Shantideva's Siksasamuccaya and Thub bstan chos gras' rGyal sras yon tan bun bzang. There is anappendix in trying to elucidate "the benefits of generating bodhicitta upon the body and the mind" from the viewpoints of psychology and medical science. The practice of generating bodhicitta has four psychological function: 1. Give the ultimate meaning to life so as to get rid of the existential vacuum on deep level. 2. Form the positive self-expectation so as to inspire the whole potential of life. 3. Dilute the feeling of inner loneliness so as to arouse great compassion of oneness. 4. Awaken the spiritual need on deep level so as to strengthen the psychological drive to practice. These four positive psychological effects will help the secretion of β - endorphin in brain so as to enhance physical health.