The kinetics of a field-induced magnetic phase transition from antiferromagnetic (AF) to ferrimagnetic (FI) state in manganese (II) bis (haxafluoroacetilacetonate), Mn(II)(hfac)(2) has been studied using the ac susceptibility and the pulse field magnetization measurements. The compound shows a metamagnetic AF-FI transition at a field of 0.02 T. The strong frequency dependence of the ac -susceptibility and the enhanced value of its imaginary part in the vicinity of the AF-FI transition have been observed. In pulse fields an increase of both the critical transition field up to about 0.1 T and the remanence were detected. The remanence disappears within the time of about 0.5 s. The peculiarities of the magnetization process in Mn-II(hfac)(2) are likely to be associated with the slow dynamic switching of the magnetization of chains at the domain wall motion in the intermediate state where both the AF and Fl phases coexist.