This paper is trying to find out the mortuary rituals of the Naxi based on the sutra of ≪Dongba Classics≫. According to the sutra of ≪Dongba Classics≫ related to the perennial youth and long life, the Naxi regard the death as an ineluctable destiny. The mortuary rituals of the Naxi are divided into two parts, that is, ''Xi Kai(西開)'' to cremate a dead body and ''Xi Wu'' to deliver the dead''s soul. The Naxi believe that the dead''s soul is sent to the place of ancestor''s domicile, namely Mt. Junashenluo(居那什羅山) and believe in the immortality of the soul. While holding the mortuary rituals, Dongba recite sutras fit for the process of the rituals according to the social position and personal history of the dead. These sutras recited in the mortuary rituals regard the death not as breaking off with the life, but as the process of being converted to nature and the continuity of life in Mt. Junashenluo. In the mortuary rituals of the Naxi, the religious paintings is used to guide the soul of the dead. The religious painting is divided into three parts, that is, the world of mortals, the world of ghosts and the world of Gods. Besides the Naxi''s own religious view, the diverse elements of foreign cultures are fused together in the religious painting.