We developed agar micro-gel oil suspensions using a W/O emulsion system. Namely, agar hot aqueous solution was dispersed in the oil phase with emulsifier at high temperature, and then the W/O hot emulsion is cooled. As a result of this procedure, the inner phase is gelled with agar. Finally we can obtain perfect spherical agar micro-gel oil suspension using the novel procedure. A new type of low fat food can be made by substituting oil phase for the agar micro-gel oil suspension. We attempted to prepare a series of low-fat mayonnaise using the agar micro-gel oil suspensions. A model mayonnaise which contains 65% oil was prepared as a control (M100). A low-fat mayonnaise which was made by using the agar micro-gel oil suspension as its oil phase. Since the agar micro-gel oil suspension contained 50 wt % agar micro-gels, the oil contents of this sample reduced 50% in comparison with M100 (M50+agar). We also prepared another model mayonnaise that 50% of oil contents were replaced with water as negative control (M50). We measured rheological properties of these samples. The apparent viscosity of M50 decreased in comparison with M100 dramatically, however, consistency drop of M50+agar was minimal. We also analyzed the frequency dependence of the complex modulus using a weal-gel model. This analysis revealed that agar micro-gels worked as viscosity thickener in the aqueous phase. It can be expected that the texture of the low fat mayonnaise made by this new method is similar to a full fat mayonnaise.