Abstract: This paper focuses on the analysis of mechanical properties of 64 rock samples collected from Permo-Carboniferous Coal Measures, Pingdingshan,Henan Province.The work reveals that the strength of rocks closely relates to the depositional environments in which the rocks were deposited.The strength of rocks is mainly dependent on （1）lithologic character; （2）hydraulic energy;（3）fluctuating features of hydraulic conditions; and （4）biological activity in the depositional environments.