Objective:A big amount of surfactants were in need to form microemulsions and consequent toxicity restricted the application of microemulsions.To decrease the amount of surfactants in microemulsion is necessary.Our present research showed that mixing oils could enlarge the domain of microemulsions and reduce the amount of surfactants.But it is unknown whether lower amount of surfactants in microemulsions induce lower bioavailability or not.The purpose of this research is to study the factors influencing the domain of mixing oils microemulsions and confirm whether lowing amount of surfactants in microemulsions induce lower bioavailability or not.