Abstract: Theoretical analysis is carried out on relationship between crack arrest toughness K_ca, crack arrest temperature T_K and crack arrest stress σ_ca in temperature-gradient double tension crack arrest test.Results indicate that there is a linear relation between crack arrest toughness K_ca and crack arrest stress σ_ca, while the linear coefficient is determined by specimen width W_s, temperature field parameters (T₁₅₀ and G_T) and crack arrest temperature T_K. Statistical analysis of 21 groups of test data confirms the validation of this relationship.