Combining the regulation of the navigable waterway in the Minjiang River Estuary, more than 130 surficial sediment samples ware collected in the Estuary area. Based on analysis of the sediment texture,fiver-mouth bar type and hydrodynamic condition, the sediment distribution pattem and sedimentation mechanism of the estuary are invertigated. The major conclusions are summarized below. 1 ) The Minjiang River Estuary can be divided into three sediment areas, i. e., sandy, mixed and muddy sediment areas, and they present delta front, front slope and prodelta sedimentary environments, respectively. 2) Because of the difference between runoff and tidal-current intensity of various distributary channel, the estuarine processes of the channels are distinct. The runoff plays a major role in the development of the Chuanshi Channel, and the tidal current is a principal factor of building the Meihua Channel. 3) The type of the fiver-mouth is restricted by the diffusion pattem of the output flow. There are various types of the rivermouth bars in the Minjiang River Estuary. The bar of the Chuanshi Channel is a subaqueous jetted type. On the north side of the Wuzhu Channel grows the subaqueous jetted sand bar. A middle ground bar is located at the outlet of the Yundou Channel. The bar of the Meihua Channel consists of a series of tidal ridges.%结合已有的闽江河口航道整治研究成果，在该河口采集了130多个表层沉积物样品。根据对沉积结构、河口沙坝类型和水动力条件的分析，探讨了闽江河口沉积物的分布规律和沉积作用机制。研究结果表明，1)闽江河口可划分为砂质、混合和泥质3个沉积区，它们分别代表三角洲前缘、前缘斜坡和前三角洲沉积环境；2)闽江河口各汊道径、潮流强度对比不同，河口沉积过程有显著差异。径流在川石水道的发育中居主导作用，潮流是塑造梅花水道的主要因素；3)河口沙坝类型受制于输出水流的扩散形式，闽江河口有多种类型的河口沙坝，川石水道的河口沙坝类型为水下突堤型，乌猪水道北侧发育了水下突堤型沙坝，熨斗水道为拦门沙型河口沙坝，梅花水道则是潮流脊型的河口沙坝。
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