The intrinsic carrier concentration is the important parameter for researching strained Si1-xGex materials properties and evaluating Si-based strained devices parameters. In this paper, at the beginning of analyzing the band structure of strained Si1-xGex/(101)Si, the dependence of its effective densities of states for the conduction and valence bands (Nc, Nv) and its intrinsic carrier concentration (ni) on Ge fraction (x) and temperature were obtained. The results show that ni increases significantly due to the effect of strain in strained Si1-xGex/(101)Si. Furthermore, Nc and Nv decrease with increasing Ge fraction (x). In addition, it is also found that as the temperature becomes higher, the increase in Nc and Nv occurs. The results can provide valuable references to the understanding on the Si-based strained device physics and its design.