The high values of recycled acrylonitrile-butadiene-styrene plastics (rABS) have drawn wide attentions and research interests. Herein, the renovation of molecular chains and phase interface of rABS was successfully achieved through simple melt-blending modification, in which the in-situ chain extension reaction was conducted between rABS and pyromellitic dianhydride (PMDA). PMDA acted as a chain extender with hydroxyl units. The modified rABS were characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), mechanical properties testing, scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA). The results indicated that compared with rABS, the molecular weight, impact strength, tensile strength, storage modulus and loss modulus of modified rABS were apparently improved. Especially, when PMDA content was 0.9 wt%, the notch impact strength reached 15.9 kJ/m(2), which was 140% higher than that of rABS. Besides, the interface between polybutadiene (PB) phase and styrene-acrylonitril copolymer (SAN) phase was blurred and the compatibility between two phases became better. The aforementioned results revealed that rABS has been achieved with high-value recycling usage. (C) 2017 Published by Elsevier Ltd.