The influence of soil pore water properties on soluble nickel (Ni) phyto-toxicity based on soil pore water and 0.01 mol/L CaCl2 extraction was investigated using 17 Chinese soils. Results showed that the effective concentrations of Ni in soil pore water (PW-Ni) that caused 50% inhibition (EC50) varied widely from 1.02 to 8.91 mg/L, represented 8.7 folds differences between the maximum and minimum values. Similarly, the EC50 of CaCl2-Ni varied widely from 0.77 to 20.40 mg/L, represented 26.5 folds differences. These results indicated that soil solution properties greatly influenced the toxicity thresholds of soluble Ni in a wide range of soils. The K+, Mg2+ and S were three important factors controlling the influence of PW-Ni toxicity and multiple regression results showed that they could better predict the toxicity threshold with the coefficient of determination (R2) of 0.71. When incorporating other parameters (dissolved organic carbon (DOC), pH, electrical conductivity (EC), Ca2+ and Na+) into the regression models, the R2 for EC50 increased to 0.84, which implied that other factors also influenced the PW-Ni toxicity and these soil pore water chemistry could predict PW-Ni toxicity on tomato shoot.