Abstract: An environmental protection and sanitary straw cap is revealed. The straw cap is a hollow tube in which one end is a close end and the other end is an open end. A straw is inserted into the straw cap through the open end. A cut is arranged at a wall of the straw cap and part of the wall of the straw cap opposite to the cut is a connection section. The width of the connection section is smaller than a diameter of the straw cap. Thereby the straw covered with the straw cap achieves sanitation. Moreover, the straw cap is environmental protective due to the reduction of material used in production of the straw cap that covers only one end of the straw and its reuses. Furthermore, the straw cap can be applied to both straight straws and bendable straws. The applicability of the straw cap is enhanced.