In this paper, a method is proposed to determine the fracture toughness of brittle and heterogeneous material through hydraulic fracturing. The intent of the proposed method is to deploy it on materials whose are not easily determined by standard test. One example of such a material is hydrate-bearing sand, which is unstable under atmospheric pressure and temperature. The pressure-time record, injection flow rate and total volume injection are necessary information to determine the fracture toughness of the material using the classical linear elastic fracture mechanics approach. To verify the method, frozen sand is used as a substitute material and its fracture toughness found using the standard test. Frozen sand has similar composition as natural hydrate-bearing sediment except for the absence of methane gas and high pressure. Then, this method is applied on the hydrate-bearing sand.