Traditional mayonnaise has some dietary health problems such as high cholesterol, high fat and high calories. In this work, the mayonnaise-like emulsions with cholesterol-free and high omega-3 unsaturated fatty acid were prepared with whey protein (WP) and Konjac glucomannan (KGM) instead of egg yolk, and linseed oil as the oil phase. The effect of flaxseed oil concentration on the physical stability, such as appearance, droplet size and microstructure, stacking and extrusion formability, and rheological properties of mayonnaise-like emulsions were investigated. The results showed that the droplets size was decreased from 30.8 µm to 17.1 µm and the uniformity of droplet-size increased with the increase of oil phase concentration. The microstructure observation showed there was no flocculation among droplets indicating a good dispersion. Moreover, when the oil phase concentration was increased from 40% to 80%, the rheological properties of the mayonnaise-like emulsion were changed from fluid properties (G′>G″ at 40%) to solid gel properties (50%~80%, G′>G″). The viscosity, elastic modulus and viscous modulus were all increased with the increase of oil phase concentration, suggesting the ability to resist deformation under a certain external force and to return to the original state after deformation was gradually enhanced. The stacking property and extrusion formability were also increased with the increase of oil phase concentration. In conclusion, by adjusting the concentration of flaxseed oil, mayonnaise-like emulsion( flaxseed oil concentration: 40%~60%) with low viscosity and strong fluidity could be prepared for use in sauces and condiments with high fluidity and dispersity requirements, or mayonnaise-like emulsion (flaxseed oil concentration: 70%~80%) with high viscosity and strong stacking property could be prepared for use in condiments with molding and coating requirements.