Buddhasri was born in 1339 (d.1432 [p3296]) as the son of Gusri Peljor Lekpa (gu shrI dpal 'byor legs pa) and Drolma Bum (sgrol ma 'bum) at the monastery of Gopu (sgo phu) in the Dok (mdog) region of Lato Jang (la stod byang). His father was then the abbot of Gopu, and his mother had tried to abort her unborn child by taking lots of "cleansing medicine" (sbyong sman) because she feared the shame that would come over her family if people would come to know that Peljor Lekpa had fathered a child. Buddhasri's father had once served as the attendant of the imperial preceptor Kunga Gyeltsen (kun dga' rgyal mtshan, 1310-1358), the originator of the Lhakhang Labrang (lha khang bla brang) branch of Sakya Monastery (sa skya). After 1361, Kunga Gyeltsen travelled to Yuan China and also Mongolia, where he was responsible for making the printing blocks of a commentary on the Kalacakratantra.