Abstract:To study the effects of farmland on macroinvertebrates, macroinvertebrates were collected from the north and south tributaries of Taizi River. And their response to farmland was discussed using non-metric multidimensional scaling analysis (NMS) and canonical correspondence analysis (CCA). The results show: The north tributary of Taizi River species composition mainly was Chironomidae, followed by Trichoptera and Ephemeroptera, and Hymenoptera in less relative abundance; while the south of tributary mostly were Ephemeroptera, Hymenoptera and Trichoptera, and the relative abundance of Chironomidae declined. Meanwhile, the main functional feeding groups of the north tributary were collector-gatherers and collector-filterers, scrapers and predator were less, almost no shredders; but the south tributary had various functional feeding groups, collector-gatherers and scrapers were more. There were significant differences on water temperature, pH, conductivity, suspended solids (SS), total dissolved solids (TDS) and total nitrogen (TN) between the north and south tributaries of Taizi River. Water temperature, conductivity and TDS of the north tributary were significantly higher than that of the south tributary; the water of two tributaries was all alkalescent water, and the average pH of the south tributary was higher than that of the north tributary; the SS and TN of the north tributary were slightly higher than that of the south tributary. Using CCA to carry out the land use factors impact on water quality, the result showed that farmland area ratio on the first axis of the contribution rate was highest in reach scale and river corridor scale, respectively -0.76 and -0.79; and the correlation between water quality factors and land use was 0.84 on river corridor scale and 0.71 on reach scale. From the CCA analysis between land use types and species can be seen, on the directions of farmland, beach and residential land mostly were tolerance and moderate tolerance groups, but fewer species distribution along the direction of farmland. On the contrary, in the fourth quadrant opposite of the dry land axis mostly were Baetidae (such as B.bicaudatus) and other sensitive groups.