One single strains(Lactococcus lactis) and two mixed strains(Lactococcus lactis: Lactobacillus casei(1∶1), Lactobacillus Helveticus: Lactobacillus casei(1∶1))were used to make start cultures, then were used to make semihard cheese. The start cultures’influence on cheese was researched by mensurating the quality of mature cheese. The result indicates, the cheese made by Lactobacillus Helveticus: Lactobacillus casei (1∶1) has the highest value on sensory assessing, which has a obvious distinction with the cheeses made by the two other start cultures. Combining with other quality indexes, Lactobacillus Helveticus: Lactobacillus casei (1∶1) is conformed as the optimal start culture to make semihard cheese.