Abstract: The concept that quarks (or aces) are the fundamental building blocks of "elementary particles" was proposed independently by Gell-man and Zweig in 1964. Since then, the field has always been at the frontier of particle physics. After 50 years of development, numerous outstanding achievements both in experiment and theory have been accomplished. In this paper,how the quark (or aces) was proposed and the subsequent development of theoretical and experimental investigations are briefly reviewed.