In this study, goat milk was concentrated by vacuum concentration to study the effect of different concentration of goat milk (12%, 14%, 16% and 18%) on the quality of yogurt.The quality of goat milk yogurt was analyzed by determination of the coagulation characteristics, texture, flavor substances, and viable counts of lactic acid bacteria. Meanwhile, the microstructure of yogurt fermented with different concentration goat milk was observed by scanning electron microscope. The results showed that the fermentation time decreased with the increase of goat milk concentration, accompanied by the increment in acidity and water holding capacity; High concentrations of 2,3-butanedione and acetaldehyde were recorded in yogurt fermented with goat milk with solids of 16%. The viscosity of goat milk yogurt increased by 149.07% with the total solids of goat milk increased.Yogurt fermented with goat milk with solids of 16% displayed with goodtexture characteristics evaluated by the hardness, adhesiveness and gumminess and cohesiveness; The viable counts of lactic acid bacteria in the yogurt was 6.35×10⁹?cfu/mL which is the highest among different milk concentration.The most compact microstructure was measured in yogurt fermented with 16% goat milk with pore diameter of 2.85?μm. In conclusion, when the concentration of goat milk is 16%, goat milk yogurt showed the best quality measured by the flavor and texture characteristics, and viable counts of lactic acid bacteria.