Abstract: A steady-state ionosphere physical model at mid and low-latitudes covering the altitude from 60 km to 120 km is preliminary established by taking several physical processes (i.e., ionization, recombination, attachment, etc.) into account and solving the continuity equation. This physical model includes 23 positive ions, 11 negative ions 12 neutral particles and 145 ion chemical reactions. The simulation shows that NO⁺, NO⁺ hydration and H⁺ hydration are the primary components of the positive ions in the whole altitude, while CO₃^- and O₃^- are dominant only below the altitude of 80 km, which results that the electron density is much less than ions. Furthermore, the comparison is conducted between the physical model and international ionosphere reference 2016 (IRI-2016) at three locations(5°N, 25°N, 45°N)along the 100°E, which demonstrates that this physical model is able to represents the morphological characteristics of altitudinal variability, diurnal variability of low altitude ionosphere at mid-low latitudes.