A method is provided for controlling a urea injection amount of a vehicle that controls urea injection in consideration of a difference between an internal temperature change rate and a regeneration temperature of an SCR integral diesel particulate filter. The method includes: detecting a regeneration temperature rising rate when in a regeneration mode; stopping, if a regeneration temperature rising rate exceeds a predetermined first reference, injection of urea, and controlling, if a regeneration temperature rising rate is less than a predetermined first reference, urea injection; controlling, if a temperature decreasing rate according to urea injection is less than a predetermined second reference while regenerating the filter, correction of an injection amount of urea; and controlling, if a difference between a target regeneration temperature and an actual regeneration temperature exceeds a predetermined third reference according to urea injection while regenerating the filter, correction of an injection amount of urea.