A liquid developer includes an insulation liquid containing a fatty acid monoester and toner particles comprised of a resin material, the resin material containing a first resin component and a second resin component of which weight-average molecular weight Mw.sub.2 is larger than a weight-average molecular weight Mw.sub.1 of the first resin component. The first resin component and the second resin component are characterized in that the weight-average molecular weight Mw.sub.1 of the first resin component is in the range of 3,000 to 12,000, the weight-average molecular weight Mw.sub.2 of the second resin component is in the range of 20,000 to 400,000, and when an amount of the first resin component contained in the resin material is defined as A (wt %) and an amount of the second resin component contained in the resin material is defined as B (wt %), A and B satisfy a relation: 1.0.ltoreq.A/B.ltoreq.9.0. The liquid developer described above is harmless to the environment. Further, the liquid developer also has superior preservability and storage stability and superior fixing characteristics at a low temperature. An image forming apparatus that can suitably use such a liquid developer is also provided.