In order to study the indicating effect of the particle size of river sediments to the regional climate change, three representative sedimental sections were collected in the middle and lower reaches of the Haohe River bed. The grain size of the sediments and quartz tail-sands were measured. The results showed that the three representative sedimental sections can be divided into four sub-layers. The first sub-layer sediments is mainly fine silty sand, the second, the third and the fourth sub-layer sediments are mainly coarse silty sand. Grain size frequency distribution curves of the second, the third, and the fourth sub-layer are very similar to quartz tail-sands. This showed that the grain size characteristics of sediments was controlled by quartz tail-sands when a great deal of quartz tail-sands was discharged into Haohe River. The results also showed that grain size of Haohe River sediments changed with the river power in the past 30 years, which was connected with the natural variations such as rainfall, flood, and so on. The peaks of the sedimental average particle diameter had corresponding relation with the years when heavy rain or flood occurred. The grain size characteristics of Haohe River sediments could indicate the climate change of Haohe River basin: when the grain size of sediment was big, it indicated more rainfall humid climate; when the grain size of sediment was small, it indicated less rainfall arid climate.