Rubber is an ideal material for most of engineering products such as tyres, seals, engine mounts, bushes, belts and hoses. In the service application, high crack growth resistance is desired to minimize premature failure associated with dynamic or cyclic induced cracking. Currently, the most widely known and standardized apparatus for crack growth test is the De Mattia according to ISO 132 and ISO 133 test methods. However, the interpretation of the De Mattia test results is very subjective and operator dependent. As such the fracture mechanics approach is widely used to characterize the crack growth resistance of rubber vulcanizates. The most common test pieces to determine the tearing energy or the crack growth resistance of vulcanized rubber are trouser tear, pure shear, parallel strips with edge and angled type test pieces. The tearing energy theory developed by Rivlin and Thomas (Lake et al., 1964a; Rivlin et al., 1953; Thomas, 1958) has been used successfully in various types of fracture of rubber like materials such as tearing, fatigue, abrasion, cutting by sharp object and cyclic crack growth.