The invention provides a nursing bottle with a biased nipple, and belongs to the industry of infant and children supplies. The nursing bottle comprises a bottle body, a bottle cap, a nipple with a one-way vent valve and a dustproof cover, wherein an outer thread is formed in an opening end of the bottle body; an inner thread and a center hole are formed in the bottle cap; the nipple is arranged in the center hole; the outer thread of the bottle body is connected with the inner thread of the bottle cap to form a sealed space; a feeding opening and at least one one-way valve which protrudes inwards are arranged on the nipple; an air intake opening is formed in the top part or the side surface of the one-way valve; an annular groove which is used for relieving deformation of the nipple and surrounds the one-way valve is arranged at the periphery of the root part of the connected part of the inside of the nipple and a large arc surface; an annular body which protrudes upwards is arranged on a seal edge of the lower part of the nipple for preventing the nipple from falling off; the annular groove which protrudes out of the annular body downwards and sinks into the bottle cap upwards is arranged at the lower part of the edge of the center hole of the bottle cap; a bulge body aligned with the dustproof cover is arranged on the edge of the outer surface of the bottle cap; and a leak-proof device which is in contact with the feeding opening of the nipple and is used for preventing a liquid in the bottle body from flowing outside is arranged in the top part of the dustproof cover; and a groove aligned with the feeding opening of the nipple after the feeding opening of the nipple and the bottle cap are clamped is arranged at the inner side of the edge.