Abstract: A water purification apparatus for increasing oxygen concentration in water. The water purification apparatus includes a water pump provided in a water tank for pumping water to produce a water flow, an ejector connected to the water pump for mixing the water from the water pump with air and ejecting the water mixed with the air therethrough, an air intake pipe connected to the ejector for supplying air thereto, and a jetting outlet connected to the ejector and formed with a porous jetting nozzle having small punched openings on an end portion and outer circumference thereof and a bugle-shaped tube accommodating the porous jetting nozzle therein.