[en] In hydrogen pellet injection experiments on the HL-1M tokamak , from multi-channel H_α signals detected with a 20 -channel PIN detector array located on the top port at the poloidal cross-section where the pellet injecting port is, the H_α radiation intensity profile is obtained with Abel inversion and the pellet location varied with time, namely the pellet penetration, is found. The scaling relationship of the pellet penetration depth with electron temperature and electron density is analyzed. And the relative variation for the whole particle confinement time is also analyzed according to the HCN multi-channel signals of electron density and the signals got from a 22-channel PIN detector array on the horizontal port at an angle 115 degree from the pellet injecting port