Traditional 3R-rules have been regarded as behaviour rules for developing recycling economy. However. with the development of modern advanced manufacturing techniques, the important value of remanufacturtng in promoting recycling economy has been given more and more attention to in recent years. Remanufacturing engineering technology, which utilizes advanced surface engineering and forming technology, produces directly with useable components of scraped machines. It can conserve the most of materials (about 85%-95%) and energy (about 80-85%) of original products with less pollution. By remanufacturing, we can reduce resources' consumption under the condition of meeting the needs of social and economic development. Remanufacturing is an advanced method for recycling economy in industry. Therefore, we think that the rules of recycling economy in industry could be extended from 3R-rules to 4R-rules. The 4R-rules' optimal sequence would be reduce,reuse, remanufacture, and recycle.