Mixtures of model lipid systems containing high‐melting and low‐melting lipid classes were crystallized and microscope images obtained for analysis of crystal morphology and microstructure. Rheological properties of these semisolid systems were tested by use of a texture analyzer. The nature of the highmelting component in a mixture dominated the crystal morphology and, combined with interactions between crystalline and liquid materials, resulted in different microstructures that influenced the rheological properties. In addition to size, shape, and amount (solid fat content) of crystalline material, the crystal packing density, representing how densely the crystalline particles in every level (individual, aggregate, or floc) were arranged, and the nature (or strength) of the link (or bridge) connecting the crystalline particles were important microstructural factors to determine rheological properties. Depending on different crystal packing densities and linking bridges, two different systems were identified in terms of microstructure type—mobile and immobile—in which the relative mobility of microstructural components had different levels. These mobility levels led to different rheological responses.