Abstract: A row of ＂dominoes＂ gradually increasing in height falling in sequence after the first is displaced,in which the total gravitational potential energy of system decreases and a part of gravity potential energy is transferred into the rotational kinetic energy of next domino.The rotational kinetic energy of falling domino has a certain relationship with the system energy transformation according to the angular momentum theorem.The condition of dominoes falling is determined by space,height of two adjacent dominoes and the angular velocity of next domino.

Key words: dominoes, height, energy transformation, height limit