Accumulation type fuel injection system

A common rail (4) of an accumulation type fuel injection system has a common rail main body (4a), distributing portions (4b) and accessory portions (4h). The common rail main body (4a) provides an accumulation chamber (4c) for accumulating high-pressure fuel discharged from a high-pressure supply pump (3). The distributing portion (4b) can be connected with a pressure introduction pipe (15) for introducing the accumulated high-pressure fuel to an injector (2) mounted to a cylinder. The accessory portion (4h) is disposed on a fuel outlet side of the distributing portion (4b) and is connected with the distributing portion (4b) and the high-pressure pipe (15) in thread connection. The accessory portion (4h) has a sealing member (4d) between the accessory portion (4h) and a connection object (4s) on the distributing portion (4b) side. The sealing member (4d) has a sealing surface (4d1) formed substantially in the shape of a spherical surface on the connection object (4s) side.