Crude tallow samples were used in pyrolysis and supercritical water liquefaction processes. The tallow from animal sources is commonly used in soap production. In tallow the saturated fatty acid component accounts for almost 50% of the total fatty acids. The reaction parameters of pyrolysis are temperature and resistance time. The reaction parameters of supercritical water liquefaction are temperature, ratio of steam-to-tallow, and resistance time. The yield of diesel-like liquid from pyrolysis of the tallow increases from 24.6 to 33.9% with increasing of temperature from 725 to 875 K and then sharply decreases. The yield of diesel-like liquid from supercritical water liquefaction of the tallow increases from 22.3 to 34.1% with increasing of temperature from 650 to 800 K and then slightly decreases.