Nanoemulsions, an emulsion system containing particle sizes from 20 to 200nm play an important role in cosmetics and pharmaceuticals industries. Phase inversion temperature (PIT) method, one of the low energy and surfactant techniques, produces nanoemulsions by heating an emulsion system to a temperature close to PIT point followed by a quenching process as it works with the changes in affinity of a non-ionic surfactant with temperatures. However, the effects of salt in the production of O/W nanoemulsions by PIT method are not well-understood. In this study, the formation and stability of n-dodecane/non-ionic surfactant (Brij30)/NaCl nanoemulsions with different salt concentration and surfactant from 4 to 8wt% and produced by PIT method would be investigated. The stability of nanoemulsions was assessed by dynamic light scattering technique by measuring the changes of particle sizes and polydispersity as a function of time and temperatures. The changes of conductivity curves for determining phase inversion were same in low surfactant concentrations. PIT points were found to decrease when NaCl concentration was increased especially from 5 to 7wt% Brij30. At the storage temperature (20oC), the initial particle sizes decreased when NaCl concentration increased. However, the decrement only existed from 4 to 7 wt% Brij30 while no nanoemulsions could be produced at 8wt%. By adding salt, surfactant concentration for the most stable nanoemulsions was reduced to 6wt% from 7wt%. Therefore, similar stable nanoemulsions could be produced with less surfactant in brine system. Furthermore, the ageing nanoemulsion could be reproduced to their fresh-prepared state by heating and cooling process.