The invention relates to water supply and drainage equipment, and concretely provides a water seal assembly and a washing machine including the same. The invention aims to solve the problem that an injection tank of a conventional washing machine is prone to leaking steam and causing user complaints. For the purpose, the water seal assembly of the invention includes a water storage cover and a downstream water pipe which is accommodated in the water storage cover, the water storage cover and the downstream water pipe are connected to each other to form a cavity, water can enter the cavity through the downstream water pipe, and the bottom of the cavity can accommodate a portion of water so as to form water seal at the bottom of the water storage cover, thereby effectively preventing a largeamount of gas from flowing through the water seal assembly. Meanwhile, the water storage cover is provided with a water drainage outlet, the downstream water pipe, the cavity and the water drainage outlet form a water inlet channel, and so the water seal assembly can prevent the gas from flowing and effectively ensure the flowing of water.