By the experimental system for collecting the charge-induced signal of the coal

the law of charge induction of coal in the different mine in process of the coal deformation and fracture is studied under different loading rates in laboratory.The experimental results show that the charge-induced signal is generated in the initial load of coal.With the increase of the loading stress level

the charge-induced signal is generated constantly

and the signal amplitude increases.Before and after the peak stress of coal

the strongest charge-induced signal is generated

and the signal is also the most abundant.After the main rupture of coal

the evident charge-induced signal is still generated

but the signal amplitude is smaller.The stronger signal of charge induction produces during coal stress mutation.The higher compressive strength of the coal and the stronger bump-prone of the coal are

the stronger the charge-induced signal is and the longer the signal duration is.The greater the loading rate is

the stronger the charge-induced signal is.Our result suggests that the charge production is relation to the deformation and fracture of coal and coal type

the coal damage degree under load may be determined from the charge-induced signal.