An aerating bag has a body, a connector, a check valve and an intake valve. The body has a connecting tube, a mounting tube and a chamber. The chamber communicates with the connecting tube and the mounting tube. The connector is detachably connected to the body and has a connecting pipe, an inserting pipe, a mounting recess, a release pipe and a cover. The release pipe is formed on and protrudes from the connector and communicates with the connecting pipe and the inserting pipe. The cover is mounted on the release pipe. The check valve mounted in the mounting recess and has an open end, a closed end and a slit. The slit is formed longitudinally in the check valve near the closed end and communicates with a clearance between the connecting pipe and the check valve. The intake valve is detachably mounted in the mounting tube of the body.