Charge distribution studies for heavy-mass fission products were carried out in the fast-neutron–induced fission of 232Th, 238U, 240Pu and 244Cm using radiochemical and gamma-ray spectrometric techniques. The width parameter(σZ /σA), the most probable charge/mass (ZP/AP), the charge polarization (∆Z) and the slope of charge polarization [δ( ∆Z )/δA′] as a function of the fragment mass (A′ )were deduced. The average charge dispersion parameter ( ‹ σZ › ) and proton odd-even effect (δp) were also obtained for these fissioning systems. The ‹ σ Z › and δp values in the fissioning systems 241Pu* and 245Cm* were determined for the first time. The δ(∆Z) /δA′ value is also determined for the first time in the fissioning systems 239U*, 241Pu* and 245Cm*. These data along with the literature data for even-Z fissioning systems such as 230Th*, 232Th*, 233U*, 234U*, 236U*, 238U*, 239Pu*, 240Pu*, 242Pu*, 246Cm*, 250Cf* and 252Cf (SF) are discussed in terms of nuclear structure effect and dynamics of descent from the saddle to the scission point. The role of the excitation energy in low-energy fission is also discussed.