A method for evaluating brittle crack arrestability of a steel plate, the method comprising using a rectangular large test piece, cooling the large test piece to a predetermined temperature, applying a predetermined stress to the cooled large test piece in a stress-application direction, wherein the stress-application direction is the length direction of the large test piece, forming a crack propagating in the stressed large test piece, and evaluating brittle crack arrestability of the steel plate, wherein the large test piece is a test piece having a width of 500 mm or more and a length of 500 mm or more taken from the steel plate, a notch, at which a brittle crack is generated, is disposed on one edge in a central portion of the one edge in the stress-application direction of the large test piece, a rectangular embrittled region which is perpendicular to the stress-application direction, formed by fusion welding on a narrow region in the propagating direction of the crack by using an electron beam welding method, having a predetermined length L extending in a propagation direction of the brittle crack is formed at a tip of the notch or formed so as to include the tip, and a rectangular fusion zone spaced from the embrittled region and which is arranged parallel to the embrittled region is formed in at least one location in the test piece after the embrittled region is formed, the fusion zone being formed at a position satisfying expression below and having lengths satisfying expressions and below: 1.0 t ≤ d ≤ 7.0t where d: distance in mm between a center of the embrittled region and a center of the fusion zone and t: thickness in mm of the test piece taken from the steel plate, − 0.3 L ≤ Δ L 1 ≤ 0.3 L 0 ≤ Δ L2 ≤ 0.4 L where L: length in mm of the embrittled region, ΔL1: distance in mm in the propagation direction of the brittle crack between a front edge of the embrittled region and a front edge of the fusion zone where negative value denotes a position on a non-evaluation region side from the front edge of the embrittled region and a positive value denotes a position on an evaluation region side from the front edge of the embrittled region, and ΔL2: distance in mm in the propagation direction of the brittle crack between an edge of the test piece and an edge of the fusion zone, wherein the width of the embrittled region is in the range of 1 mm to 10 mm, the width of the fusion zone is in the range of 0.5 mm to 30 mm, the non-evaluation region is a region in which the generated brittle crack propagates through the embrittled region, and the evaluation region is a region in which the embrittled region does not exist and which is made only of the material of the steel plate, and the non-evaluation region is a region which is located before the evaluation region seen from the direction in which the crack propagates and in which the embrittled region exists. the large test piece is a test piece having a width of 500 mm or more and a length of 500 mm or more taken from the steel plate, a notch, at which a brittle crack is generated, is disposed on one edge in a central portion of the one edge in the stress-application direction of the large test piece, a rectangular embrittled region which is perpendicular to the stress-application direction, formed by fusion welding on a narrow region in the propagating direction of the crack by using an electron beam welding method, having a predetermined length L extending in a propagation direction of the brittle crack is formed at a tip of the notch or formed so as to include the tip, and a rectangular fusion zone spaced from the embrittled region and which is arranged parallel to the embrittled region is formed in at least one location in the test piece after the embrittled region is formed, the fusion zone being formed at a position satisfying expression below and having lengths satisfying expressions and below: 1.0 t ≤ d ≤ 7.0t where d: distance in mm between a center of the embrittled region and a center of the fusion zone and t: thickness in mm of the test piece taken from the steel plate, − 0.3 L ≤ Δ L 1 ≤ 0.3 L 0 ≤ Δ L2 ≤ 0.4 L where L: length in mm of the embrittled region, ΔL1: distance in mm in the propagation direction of the brittle crack between a front edge of the embrittled region and a front edge of the fusion zone where negative value denotes a position on a non-evaluation region side from the front edge of the embrittled region and a positive value denotes a position on an evaluation region side from the front edge of the embrittled region, and ΔL2: distance in mm in the propagation direction of the brittle crack between an edge of the test piece and an edge of the fusion zone, wherein the width of the embrittled region is in the range of 1 mm to 10 mm, the width of the fusion zone is in the range of 0.5 mm to 30 mm, the non-evaluation region is a region in which the generated brittle crack propagates through the embrittled region, and the evaluation region is a region in which the embrittled region does not exist and which is made only of the material of the steel plate, and the non-evaluation region is a region which is located before the evaluation region seen from the direction in which the crack propagates and in which the embrittled region exists.