As an important urban and rural development model in the three gorges reservoir area, watershed field town development model along the river has been widely popularized, and brought a series of the complex influences of the point-like aggregation pattern for human activities on the river water environment. In this study, the Heishuitan River and its main tributaries, which are featured with obviously field town development in the basin, were selected to carry out an investigation regarding carbon, nitrogen and phosphorus concentrations in surface water from September, 2014 to June, 2015, for discussing the influence of field towns distribution on the temporal and spatial patterns of water biogenic element in the basin. Results showed that, the concentrations of TOC and DOC in the water of main stream and tributaries were 4.5-39.2 and 3.2-31.4 mg/L, and TN, NO₃^--N and NH₄⁺-N were 1.12-6.96, 0.87-5.00 and 0.073-0.881 mg/L, while the ranges of TP, DTP and PO₄^3--P concentrations are of 0.078-0.454, 0.049-0.310 and 0.025-0.222 mg/L. All of the biogenic elements in the water presents a significantly spatiotemporal variability. The concentrations of carbon, nitrogen and phosphorus increased in certain extent when the water flowed through different towns, with the increasing range of the TOC, TN and TP of 4.7%-61.3%, 26.7%-144.7% and 12.8%-50.7%, respectively. Meanwhile, the water flowed through non-town reaches, the carbon concentrations of the main stream had no significant changes, and nitrogen and phosphorus concentrations were significantly reduced, indicating that the spatial variation characteristics of water biogenic elements (C, N and P) were co-regulated by the distribution pattern of the watershed towns and its self-purification capacity, and resulting that the carbon concentrations in the main stream increased "stepwise" from the upstream to the downstream. While the nitrogen and phosphorus content showed a "fluctuation" growth trend; correlation analysis shows that the concentrations of carbon, nitrogen and phosphorus were significantly related with each other, suggested that the nutrient contents had a synchronous change trend under the development mode of the towns. This study highlights that the bead-like field towns development pattern in mountain river basin would lead an obvious synchronous accumulation of pollutants from the upstream to the downstream, and then beyond the self-purification capacity of river water. In addition, the seasonal variation of carbon, nitrogen and phosphorus concentrations in rivers were mainly affected by runoff dilution, and resulting a pattern of lower concentrations in summer and autumn, and higher in spring. The eutrophication comprehensive index indicates that the monitoring sections of the Heishuitan River were above eutrophication status, and the surface water body has serious nitrogen pollution and light phosphorus pollution. Roughly estimation of the annual input flux of TOC, TN and TP from Heishuitan River to Three Gorges Reservoir amounts to 4057, 1001 and 47 t, which poses a serious threat to the water environment security. The bead-like field town development along the river, forming a specific pollution pattern with "point-surface" dual attributes and threatening the water environment safety of the Three Gorges Reservoir, should be concerned in the future.