A method for measuring a degree of recrystallization of a zirconium alloy cladding tube for nuclear fuel, the method comprising: electrolytic polishing a fully recrystallized sample 1, a partially recrystallized sample 2 of which a recrystallization measurement is needed, and an as-deformed sample 3, then making an SEM electron beam incident onto each of the sample 1 to the sample 3 at a predetermined scan interval, and then acquiring a backscattered electron signal through an EBSD camera of each of the sample 1 to the sample 3 (step 1); using EBSD software so as to convert the backscattered electron signals acquired from each of the sample 1 to the sample 3 into pattern quality values, and calculating pattern quality values histograms as frequencies by a specific range (step 2); obtaining pattern quality frequencies B + D deviated from the pattern quality values histograms of the sample 3 among the pattern quality values histograms of the sample 2, B representing a sum of frequencies of an area where the frequency of the pattern quality distribution of the partially recrystallized sample 2 is greater than that of the as-deformed sample 3 and the fully recrystallized sample 1, D representing a sum of frequencies of an area where the frequency of the pattern quality distribution of the partially recrystallized sample 2 is smaller than that of the fully recrystallized sample 1 and greater than that of the as-deformed sample 3, and obtaining pattern quality frequencies D + E deviated from the pattern quality values histograms of the sample 3 among the pattern quality values histograms of the sample 1, E representing a sum of frequencies of an area where the frequency of the fully recrystallized sample 3 is greater than that of the partially recrystallized sample 1 (step 3); and obtaining a degree of recrystallization of the sample 2 from equation X ′ = B + D D + E × 100, % (step 4). electrolytic polishing a fully recrystallized sample 1, a partially recrystallized sample 2 of which a recrystallization measurement is needed, and an as-deformed sample 3, then making an SEM electron beam incident onto each of the sample 1 to the sample 3 at a predetermined scan interval, and then acquiring a backscattered electron signal through an EBSD camera of each of the sample 1 to the sample 3 (step 1); using EBSD software so as to convert the backscattered electron signals acquired from each of the sample 1 to the sample 3 into pattern quality values, and calculating pattern quality values histograms as frequencies by a specific range (step 2); obtaining pattern quality frequencies B + D deviated from the pattern quality values histograms of the sample 3 among the pattern quality values histograms of the sample 2, B representing a sum of frequencies of an area where the frequency of the pattern quality distribution of the partially recrystallized sample 2 is greater than that of the as-deformed sample 3 and the fully recrystallized sample 1, D representing a sum of frequencies of an area where the frequency of the pattern quality distribution of the partially recrystallized sample 2 is smaller than that of the fully recrystallized sample 1 and greater than that of the as-deformed sample 3, and obtaining pattern quality frequencies D + E deviated from the pattern quality values histograms of the sample 3 among the pattern quality values histograms of the sample 1, E representing a sum of frequencies of an area where the frequency of the fully recrystallized sample 3 is greater than that of the partially recrystallized sample 1 (step 3); and obtaining a degree of recrystallization of the sample 2 from equation X ′ = B + D D + E × 100, % (step 4). <EOS>