A burner of a gas stove includes a burner body, a partition member, and at least one flame cover. The burner body includes a gas conduit and a base. The gas conduit has at least one gas input passage for injecting gas and air, and the base has at least one mixture passage for mixing the gas and the air. The at least one mixture passage communicates with the at least one gas input passage. The partition member has a plurality of through holes and covers the at least one mixture passage. The at least one flame cover provided with a plurality of flame holes covers the partition member. Whereby, the size of the burner of the gas stove is reduced significantly, and the gas can mix with the air effectively and uniformly.