The invention provides a 3-D printing method including: providing a liquid-state forming material in a 3-D printing apparatus; detecting a temperature of the liquid-state forming material; and adjusting corresponding curing parameters according to the temperature and curing characteristics of the liquid-state forming material to cure the liquid-state forming material layer by layer, so as to form and stack multiple cured layers to form a 3-D object. The invention can ensure consistency of a molded object printed by the 3-D printing apparatus using the liquid-state forming material and thus, solve the issue of inconsistent quality occurring to the molded object printed by the 3-D printing apparatus using the liquid-state forming material due to the curing speed of the liquid-state forming material varying with temperatures.