Phase transfer technique, using benzyldimethylhexadecyl ammonium chloride as a titrant, was employed for the characterization of non-crosslinked natural rubber latex. The critical transfer concentration values were reproducible in each solvent studied and the increase was found to coincide with the decrease of the difference between the solubility parameter of organic solvent and that of natural rubber. Results indicated a complete phase transfer process in which 96% of rubber was transferred.