This paper presents a case which constructs a new slurry wall on an old basement in the business district of Taipei city. A new tall building of 28 stories with a basement of 6 stories is planned to construct on a site with an old basement of 3 stories. The alignment of the new slurry wall will run over the old basement and intersect with the old slurry wall. For the construction of the new slurry wall, the method of deep guide wall with a depth of 12 m was adopted. To ensure the stability of the 12 m-deep guide wall, special design with internal bracing and external supporting system was applied. For the dredging of new slurry wall, a special cutter is utilized to cut the concretes and steel bars in the old slurry wall. The construction method adopted worked very successfully to complete the new slurry wall designed for the renewal basement.