The authors regret that errors occurred in the previous paper (Chin. Opt. Lett. 4, 164. A phase-stepping interferometric photoelasticity method is proposed to determine whole-field sum of principal stresses. The four phase steps are introduced by rotating quarter-wave plate and analyzer at definite optical arrangements. Light intensities and phase-stepping formula for the proposed method are derived using Jones calculus. Simulations of a circular disk under diametral compression demonstrate the feasibility of the proposed method). This is the erratum to the errors.