A negative electrode active material includes particles of negative electrode active material, wherein the particles of negative electrode active material contain particles of silicon compound containing silicon compound (SiOx:0.5≤x≤1.6), the particles of negative electrode active material contain crystalline Li2SiO3 in at least a part thereof, and the particles of negative electrode active material satisfy the following formula 1 and formula 2 between an intensity A of a peak derived from Li2SiO3, an intensity B of a peak derived from Si, an intensity C of a peak derived from Li2Si2O5, and an intensity D of a peak derived from SiO2, which are obtained from a 29Si-MAS-NMR spectrum. Thus a negative electrode active material capable of increasing a battery capacity, and improving the cycle characteristics and initial charge/discharge characteristics when used as a negative electrode active material of the lithium ion secondary battery is provided. A>B>D  (1) A>C>D  (2)