The spectroscopy induced by laser can reflect the characteristics of the sample,In order to apply laser-induced break down spectroscopy (LIBS) for the direct detection of coal particles flow,this wo rk presents the experimental analysis on the coal particle flow with the laser- induced breakdown spectroscopy technology.Three kinds of coal samples (anthracit e bituminous and lignite) were chosen to explore the plasma characteristics of c oal particle flow.The relationships between the characteristics of plasma signal and the sample itself are analyzed.The characteristics of those coal samples ar e quite different and they are widly used in coal-fire power plant.Samples were ablated by 1064nm pulse laser in atmosphere.Based on the an alysis of the plasma signal collected by the spectroscopy,the relations between coal particle flow and the relative line intensity of silicon and aluminum,plasm a temperature and electron density are concluded.The analysis results show that the relative line intensity of silicon and aluminum is related to the ash conten t of the coals and its relative line intensity increases with the increasing of ash content in the coal particle flows.For the plasma temperatures and electron dens ities of the three kinds of coal samples,the results from large to samll order a re achieved:anthracite,bituminous,lignite.