The photosensitized polymerization of styrene in bulk was investigated in the temperature range of 25-70ยฐC with respect to the average rate coefficient of bimolecular chain termination k t , especially its chain length dependence at low conversions, by means of pulsed laser polymerization (PLP). Three methods were applied: two of them were based on equations originally derived for chain length independent termination taking the quantity k t contained therein as an average k t , while the third one consisted in a nonlinear fit of the experimental chain length distribution (CLD) obtained at very low pulse frequencies (LF-PLP) to a theoretical equation. The exponent b characterizing the extent of chain length dependence was unanimously found to decrease from about 0.17-0.20 at 25ยฐC to 0.08 -0.11 at 70ยฐC, slightly depending on which of the three methods was chosen. This trend toward more "ideal" polymerization kinetics with rise of polymerization temperature is tentatively ascribed to a quite general type of polymer solution behavior that consists in a (slow) approach to a lower critical solution temperature (LCST), which is associated with a decrease of the solvent quality of the monomer toward the polymer, an effect that should be accompanied with a decrease of the parameter b.