Study of the Exotic State X(3872) at BESIII

Quantum chromodynamics(QCD) allows the existence of exotic states, which beyond baryons and mesons in the quark model. The study of exotic states is one of the hot topics in high-energy experiments. X(3872) was the first candidate for an exotic particle observed experimentally. Experimental and theoretical study on X(3872) has never been stopped, which makes X(3872) also the best exotic state being understood. The Beijing Spectrometer(BESIII) Experiment at the Beijing Electron Positron Collider(BEPCII) collected large data samples for electron-positron collisions with center-of-mass energy from 3.87 to 4.70 GeV. The analysis of these data samples has resulted in a number of achievements on X(3872). In this paper, we will review the research on X(3872) at BESIII and a series of achievements and the latest progress made at BESIII. The study of X(3872) and other exotic states will help us understand the basic interactions of the nature, and it will also provide a strong support for the standard model theory.