Pomelo (Citrus grandis) trees are easy to grow and cultivate with good resistance to some dangerous pests, diseases on citrus trees, especially greening disease. It can be harvested in long period, so it has been strongly developed in recent years. However, the inconsistent application of advance techniques in production process such as: seed, planting, cultivating, harvesting, preserving, and so on has affected the growth and development of the tree, especially its fruit appearance and quality. There are many techniques which can be applied to improve the appearance and quality of Dien pomelo, including fertilizing, pruning, canopy creating, preserving... The scientists of the Institute of Regional Research and Development have studied and found a solution to help famers enhance pomelo’s appearance and quality by using fruit cover. After studying in the climate conditions of Vinh Phuc province, the scientists of the Institute have determined that covering pomelos with Chinese waterproof bags after 30 days of faded flowers helps improve pomelos' appearance and quality. Specifically, percentage of blotchy pomelo and stung by flies is low: 1.76%; percentage of edible pomelo is high: 62.16%; the pomelo has fresh yellow peel, good appearance of 9.00 points; sugar content reaches 7.57%; and Brix level: 12.2%, the amount of vitamin C: 62.56%, and acid content: 0.135%.