It is of economic and social benefit to use the fine sand of Yangtze estuary as subgrade filling, which not only can avoid the shortage of materials, but also is an effective utilization way of sands for dredging Yangtze channel. However, the engineering properties of fine sand are different from the ordinary filling materials because of the fine grain and bad gradation of the particles. So a series of laboratory and field tests were performed for five kinds of fine sand of Yangtze estuary, including the experiments of sieve analysis, compaction characteristic, water content and modulus. The diameters of fine sand mostly ranged from 0.075 to 0.300mm, the non uniform coefficient were less than 5. The maximum dry density from modified standard compaction with small tube is higher than that with big tube, because the former can avoid disturbing compacted fine sand. The compaction curve has a few peaks, and the less content of fine particle, the more numbers of the curve peak, that is useful to compaction control in field. The fine sand is usually less affected by groundwater; the modulus can meet the requirement of the design and has significant correlation with compaction degree and content of fine particle. Moreover, the performance of low subgrade with fine sand does not degrade significantly after one million load repetitions.