The plasma conditions of Ni-like Ag, Cd, In, Sn, Sb, and Ne-like Fe, Co, Ni, Cu, Zn x-ray lasers are numerically simulated, using a one-dimensional hydrodynamic code. The results suggest that there is a correspondence of plasma conditions b etween some Ni-like x-ray lasers and Ne-like x-ray lasers by comparing the hydro dynamic characteristics of electron temperature, ion abundance and ion populatio n density. For example, the plasma condition of the Ni-like Ag x-ray laser is si milar to that of the Ne-like Fe x-ray laser and the Ni-like Cd x-ray laser is si milar to that of Ne-like Co, etc. Due to this correspondence, we can use the sim ulation of those Ne-lie x-ray lasers to give suggestions of performance of this partner Ni-like x-ray lasers.