Dynamic self-assembled structures found in complex fluids containing surfactant, water, and oil, range from spherical and cylindrical swollen micelles to bicontinuous microemulsions and ordered liquid crystalline phases [1]. These structures are extensively used as templates for the synthesis of nanomaterials [2,3]. However, up to date, it is not possible to copy the microemulsion-structure to the microstructure of polymer particles on a one-to-one scale. Recently Co et al. [4,5] used a new class of highly viscous microemulsions that comprise surfactant, polymerizable oil, and concentrated water/(sucrose/trehalose) solutions to maintain the microstructure. The addition of sugar enables the kinetic of the phase behaviour to be slowed down compared to the changing monomer/polymer ratio during polymerization. In this study we systematically investigated the phase behaviour of highly viscous sucrose-microemulsions. Starting from the sugar-free nonionic system H₂O – n-octane – C₁₀E₆ the amount of sucrose within the water phase was increased up to 75%. It is found that the addition of sucrose shifts the phase behaviour to low temperatures. By replacing the surfactant C₁₀E₆ by a more hydrophilic surfactant the temperature drop can be compensated. The system H₂O/(sucrose/trehalose) – C₆MA – Agnique PG 264-G which is a highly viscous, polymerizable microemulsion was further polymerized with varying amounts of cross-linker in the oil phase and the structures were investigated by SEM and TEM. Additionally, the kinetics of the phase behaviour of systems containing various amounts of sugar in the water phase was investigated by temperature jump experiments.