To investigate the mechanisms of the oil-in-oil nanoemulsions transport through the gastrointestinal tract and the transport efficiency changed with its different particle size in the lymphatic channels.The behavior of nanoemulsions in vivo and their absorption via lymph after oral administration was investigated, with the transport efficiency and absorption pathway of nanoemulsions clarified by lymph duct cannulation in rats.It suggested about 36.8% of puerarin nanoemulsions was transported into systematic circulation via lymph. Nanoparticles with different size absorbed by the lymphatic channels varied as the degree of transportion.The degree of absorption and particle transport is inversely proportional to the size.