Depolymerization of natural rubber, using a combination of mechanical and thermal energies aided by a peptiser, has been attempted. Peptiser dosage, temperature and heating time for producing liquid natural rubber (LNR) of desired viscosity were optimised. LNR can be produced by thermal depolymerization, with or without the addition of a peptiser. Possibility to produce LNR of desired viscosity by appropriately fixing the peptiser dosage, temperature and duration of heating was revealed. As degradation was found rapid at higher temperatures depolymerization at lower temperature is desirable. Properties of the liquid rubber such as Brookfield viscosity, intrinsic viscosity, iodine value and acetone extract have been determined. IR and NMR studies were also carried out. Vulcanization of LNR with sulphur resulted in very poor strength properties.