A connecting base for suction catheters has a body (20, 20A, 20B, 20C) and a check valve (30, 30B). The body (20, 20A, 20B, 20C) has an assembling portion (21, 21A, 21B, 21C) and a jointing tube (22, 22A, 22B, 22C). The jointing tube (22, 22A, 22B, 22C) is located in the assembling portion (21, 21A, 21B, 21C). The check valve (30, 30B) has a positioning ring (31, 31A, 31B) and two valve blades (32, 32A, 32B, 32C). The positioning ring (31, 31A, 31B) engages with the assembling portion (21, 21A, 21B, 21C), and the two valve blades (32, 32A, 32B, 32C) respectively abut an edge of a positioning hole (222) of the jointing tube (22, 22A, 22B, 22C). The two valve blades (32, 32A, 32B, 32C) may close automatically to increase the airtight effect of the connecting base (10).
