This paper presents cube and dynamic cube attacks on reduced-round lightweihgt block cipher SIMON32/64, proposed by U.S. National Security Agency in 2013. Cube attack is applied to 17 rounds out of 32 rounds of SIMON using a 13-round distinguisher and dynamic cube breaks 14 rounds out of 32 rounds using 10-round distinguishers. Both attacks recover the full 64-bit key of the cipher in a practical time complexity.