Provided is a carbonated water mixing apparatus. According to an embodiment of the present invention, the carbonated water mixing apparatus comprises: a mixing portion for mixing original water and carbon dioxide, and manufacturing carbonated water a storage tank connected to the mixing portion through a transfer line, storing the carbonated water, manufactured in the mixing portion, for a certain amount, and discharging outside through a discharge line and a compressing portion installed in the transfer line, and compressing the carbonated water which is transferred to the storage tank from the mixing portion. The storage tank is arranged to make a lower side sunk in cold water stored in a cold water tank of a water purifier, and the carbonated water entered in the storage tank is naturally cooled through the cold water stored in the cold water tank. The compressing portion comprises: an expansion portion having a wider cross-sectional area than a cross-sectional area of the transfer line, and mixing the carbonated water for a second time through swirl and a first connecting portion and a second connecting portion having a narrower cross-sectional area than the cross-sectional area of the transfer line, and respectively connecting the expansion portion to the transfer line. The cross-sectional area of the first connecting portion, discharging the carbonated water to the storage tank from the expansion portion, is relatively bigger than the cross-sectional area of the second connecting portion, supplying the carbonated water to the expansion portion from the mixing portion, and is relatively smaller than the cross-sectional area of the transfer line.COPYRIGHT KIPO 2015탄산수 혼합장치가 제공된다. 본 발명의 예시적인 실시예에 따른 탄산수 혼합장치는 원수 및 탄산가스를 혼합하여 탄산수를 제조하는 혼합부 상기 혼합부와 이송라인을 통해 연결되어 상기 혼합부에서 제조된 탄산수가 일정량 저장되고, 배출라인을 통해 외부로 배출되는 저장탱크 및 상기 이송라인 상에 구비되어 상기 혼합부에서 상기 저장탱크 측으로 이송되는 탄산수를 가압하는 가압부를 포함하고, 상기 저장탱크는 하부측이 정수기의 냉수탱크에 저장된 냉수에 잠기도록 배치되어 상기 저장탱크 측으로 유입된 탄산수가 상기 냉수탱크에 저장된 냉수를 통해 자연냉각되고
