A prediction method of the critical current–bending strain relation of the Bi2223 composite tape, which was bent at room temperature and cooled down to 77K for measurement of critical current, was presented. The present method consisted of (a) measurement of residual strain of Bi2223 filaments at room temperature in the sample length direction by the X-ray diffraction method, (b) estimation of tensile fracture strain of the filaments from the analysis of the load–strain curve at room temperature, (c) measurement of geometrical factors such as the thickness of the sample and shape of the core by observation of the cross-section with optical microscope, and (d) calculation of the critical current as a function of bending strain by using the measured parameters mentioned in (a)–(c). The predicted variation of critical current with bending strain by the present approach described well the experimental one.