A composition used for thermotherapy includes a carrier structure and a plurality of metal particles. The carrier structure includes a lipid layer, a positive charged polymer and a surface active polymer. The positive charged polymer and the surface active polymer are dispersed on the lipid layer by non-covalent bonding. The metal particles are encapsulated in the carrier structure. A producing method of the composition used for thermotherapy and a method for using the composition in cancer treatment are also disclosed.
