This paper is the continuation of "Bergson's Philosophy of Life I, II, III". In "I" his own original view of philosophy has been explained. In "II" and "III" we have discussed his philosophical solutions for physiological problems of life. In this paper biological problems of life are discussed from Bergson's own philosophical point of view, especially his philosophical interpretation of evolutions of life. Bergson rejects interpreting the evolution of life teleologically and mechanically, but favors to understand it in his own sense of teleology.