Polymerization of octodecyl acrylate is studied in four solvents — carbon tetrachloride, chloroform, methylbenzene and tetrachloroethane. Experimental results indicate that the sequence of chain transfer constants in solvents is: carbon tetrachloride>chloroform>methylbenzene>tetrachloroethane in the polymerization of octadecyl acrylate. Influences of four solvents on solubility of polyoctadecyl acrylate prove not the same. In chloroform, polyoctadecyl acrylate shows the highest relative viscosity and the lowest chain termination rate constant. In higher conversion, the average relative molecular weight of polyoctadecyl acrylate depends mainly on the chain transfer constant of the solvent. Under the circumstance of monomer conversion higher than 30%, the viscosity effect induced by polymeric molecular shape in the solvents have a strong influence on the relative molecular weight of the polymer obtained. Polymerization of octodecyl acrylate is studied in four solvents - carbon tetrachloride, chloroform, methylbenzene and tetrachloroethane. Experimental results indicate that the sequence of chain transfer constants in solvents is: carbon tetrachloride> chloroform> methylbenzene> tetrachloroethane in the polymerization of octadecyl acrylate. four solvents on solubility of polyoctadecyl acrylate prove not the same. In chloroform, polyoctadecyl acrylate shows the highest relative viscosity and the lowest chain termination rate constant. In higher conversion, the average relative molecular weight of polyoctadecyl acrylate depends mainly on the chain transfer constant of the solvent. Under the circumstance of monomer conversion higher than 30%, the viscosity effect induced by polymeric molecular shape in the solvents have a strong influence on the relative molecular weight of the polymer obtained.