Since Barcelona implemented the Plan Cerdà at 1859, the city has started the process of building a modern city. A series of urban planning projects and transformations gradually formed nowadays metropolitan city. Especially after holding 1992 Barcelona Olympic Games, Barcelona has gained recognition as 'Barcelona Model' in its urban-planning efforts for the past 40 years. However, it’s certain that the processes of metropolitan decentralization experienced a spectacular acceleration precisely in the post-Olympic period where the municipal local authority of Barcelona lost number of inhabitants, jobs and economic activities coinciding with the decentralization. This paper concentrates on analysing the waterfront living spaces. There are four main situations of encounter between the city and water: along the river, around the lake, embeded in the water network and open to the sea. By studying and concluding characteristics of each corresponding case, Copenhagen, Denmark; Suzhou, China; Hamburg, Germany and Barcelona, Spain, thus summarizing a feasible waterfront living space method for the site selected of Barcelona to achieve a brand development. The paper concludes the future projects of Barcelona in the 21st century. On the threshold of a new urban planning model (Barcelona 5.0), it’s a possible approach that re-naturalization of the city and re-connection of the waterfront and the city. On the basis of researches, the paper seeks to summarize several design strategies used in waterfront living space, thus making a practice in the final design to promote 'reappear sea on the land', a new waterfront living space for Barcelona.