PRC roundel (symbol/emblem) — red star with yellow fimbriation and the "八 8"–"一 1"  PLA emblem inside the star.  (This refers to the date 1 August: the People's Liberation Army was founded on 1 August 1927 during the Nanchang uprising.)  Used also as military vehicles roundel.
Originally from zh.wikipedia; description page is/was China Emblem PLA.svg.
Original uploader was Nicolau at zh.wikipedia