Both potassium tris(oxalato)cobaltate(M), KsCo(C20Ds) qnd po.tass.iym. tris(oxalato)fgyrate (III), KFe(C, q), can sensitize the phtP, lymerizati, nsf acrylamide in aque, us solutions, 6fftheMi-r kinetic behaviors are different from one another.The rates of phtP1ymerizati, ns sensitized by the c, balt(III), mplex under irradiatin at 420UVr '6ToTdim aie giv-en'as follows R, klee'5(1-10ed)'5. This rgsult shows.the muyual eMimi'ha-ti'on of growWing polymer redicals. ln view of the low initiati-on efliciency of.the complex E-emay partly decay .sponta neo.usly aqd. pgrtly induce the decomposition 6Mi Ttfie coniplexT without the formation of radicals, besides-initiatipg the. polymgrization.On the ther hand, the ph, t, P1ymerizations sensitized by the ir, n(III), mplex under irradiati5ff it'V42Vo him' rmchn be ini-tiated wi'thout any induction period, whereas e ratg decr.ea.sep with Vesu-iiingpFoTiyF iner while the Trate of decomposition of tbe compex ip, ittle, affected by perc, hl, o.r-i-9 rt rbiYN'be' conidered that the suppression of the r.ate.is attriPuted Sg the accgmulation acid. fxalat fer rate (III) resulting frm the dec p, sti, nf ferr icc, m pl ex, Moreover, it appears tVt-h'e-V66fiilileiJi16tards the polymerization at its higher concentrations even in aeidie selutions.