Abstract: A nose plug structure incorporating a filter is provided. The nose plug is integrally formed with a connecting piece and a pair of hollow columns formed on opposing sides of the connecting piece. In the middle of the connecting piece, a soft cover piece is positioned which can cover the exits of exhalation passages formed in each hollow column. An inner net, filter material, and a stop piece are arranged in order in each hollow column. An exhalation passage is formed in each column and leads to the exit located at the back of the connecting piece. When the plug is inserted in the nasal cavity, the inhaled air is cleaned as it passes through the stop piece, filter material and inner net. The exhaled air exhausts through the exhalation passages formed in the hollow columns, forcing the cover piece open.