Sealing structure of parting portion

In a sealing structure for closing a parting portion between a front door (2) and a rear door (2) by a seal lip (40), in which: the front door (2) has a front side weather strip (20) installed on a peripheral edge thereof; the front side weather strip (20) makes elastic contact with a center pillar (4); the seal lip (40) has a substantially tongue-shaped cross section, is disposed at a rear side weather strip (10) and has a an assembly part (42) formed on a base root (41b) side thereof; and the assembly part (42) is assembled on the rear door (1); the base root (41b) side has a bending point (200) provided thereon for the seal lip (40) to be curved toward the inner-cabin side so that a top (41a) end makes elastic contact with the center pillar (4) when high pressure water (700) splashes the seal lip.