A means of correlation between the activity and the net charge, the metal atom net charge correlation (MANCC), which was successful in the activity prediction of the early-transition metal catalysts, has been used to study the catalytic activities of salicylaldiminato Ni(II) complexes, the late-transition metal catalysts, in olefin polymerization or oligomerization. A comparison with the available quantum mechanics/ molecular mechanics (QM/MM) calculation data suggests that even without a detailed mechanism, MANCC results mostly agree with QM/MM calculation data regarding insertion barrier data and enthalpy change. Eight experimental complexes were further built up by modeling; their catalytic activities predominantly increased in line with the net charges on the metal atoms. The same results were obtained for the other four complexes synthesized in the present work. (C) 2004 Wiley Periodicals, Inc.