An easily removable dental curable composition which prevents the fall or leakage of a temporary prosthetic appliance or a root canal filling material which is easily removed by bonding and adhering it to tooth, shows such high flowability that its operation is easy, has a long working time and excellent X-ray contrast properties and sealability and can be easily removed as required, and a filling kit. The dental curable composition comprises (A) a polymerizable monomer mixture containing a polymerizable monomer having an acid group in the molecule and (B) a polymerization initiator, wherein the component (A) contains (A′) a long-chain polymerizable monomer having a structure with a chain length of 17 or more atoms and/or the composition further comprises (D1) a soft resin material.