Non-equilibrium atmospheric pressure plasma has received much attention for various applications

such as biomedicine

environment

and material processing. The various reactive particles in the plasma often play an important role in these applications

thus the diagnosis of the concentrations of these particles is important to promote these applications. This paper gives a detailed review of an important non-equilibrium atmospheric pressure plasma diagnosis method

namely

laser-induced fluorescence. Firstly

the basic principle and typical experimental setup of laser-induced fluorescence are described. Secondly

the absolute density calibration processes and experiment details of single-photon and two-photon excitation cases are given. Thirdly

for the widely used reactive particles including OH

NO

O

and N

the characteristics of the temporal resolved evolution and spatial resolved distribution are analyzed and discussed. Finally

according to the characteristics and research status of laser-induced fluorescence technology

the future research directions are analyzed and discussed.