The authors have voluntarily retracted article [Zeng C, Zhang N W, Ren J. Recent progress in AFM studies of biodegradable poly(lactic acid) materials. Chin Sci Bull, doi: 10.1007/s11434-012-5052-z] because of portions of the article are similar to a previous publication [Yuryev Y, Wood-Adams P, Brisson J, et al. Crystallization of polylactide films: An atomic force microscopy study of the effects of temperature and blending. Polymer, 2008, 49: 2306–2320]. While there was no intention to use pre-existing work without appropriate attribution, the authors apologize to all affected parties for the inconvenience.