A crystalline form of epirubicin hydrochloride, named herein as "type II" crystalline epirubicin hydrochloride, has excellent thermal stability. Type II crystalline epirubicin hydrochloride has a powder X-ray diffraction pattern having average values of diffraction angle (2.theta.) and relative intensity P(%) as presented in the following table: TABLE-US-00001 Diffraction Angle Relative Intensity 2.THETA. P % 5.2 100 9.2 24.5 10.3 14.3 13.7 32.8 14.6 10.9 15.5 49.3 18 19.1 19.2 21.1 19.4 11.3 20.7 19.9 21.1 29.7 21.4 18 22 23.1 22.5 69.6 23.6 20.5 24.1 72.1 25.8 67 26.1 15.9 27.7 47.9 29.8 38 31.9 14.1 32.1 16.7 36.4 16.6 37.7 18.8 41.1 14.5