A conservative integral independent of the constitutive relation

J-integral defined by Rice depends on the constitutive relation of mediums. In the present paper, a conservative integral independent of the constitutive relation of mediums is defined in order to extend Rice's definition of the J-integral which depends on the constitutive relation. Its main properties which are similar to those of the prevailing J-integral are proved. In the case of the elastic mediums, the extensive conservative integral is the same with Rice's J-integral.