An air valve connecting device or attachment includes a housing having a tilted inner peripheral surface, a sliding member slidably engaged in the housing and having a pathway for receiving a pressurized air, a gripping device having two casing members slidably engaged with the tilted inner peripheral surface of the housing and having a passage formed in the casing members, and an inflation valve engageable into the passage of the casing members for moving the casing members into the housing and for allowing the casing members to be forced toward each other with the tilted inner peripheral surface of the housing and in order to grasp the inflation valve with the casing members.