Three species of harrier Circus with 363 individuals, including marsh harrier C.a.aeruginosus，hen harrier C.c.cyaneus and eastern marsh harrier C.s.spilonotus, were recorded when we surveyed Shahu Nature Reserve in Hubei within 186 line transects during the four years. The results indicated that the harrier abundance was significantly higher in autumns than that in winters; however, little fluctuation appeared in the harrier abundances of corresponding period of autumns and winters respectively as well as in annual abundances from the four-year survey. There was significant difference among harrier abundance in different habitats as follows: grassland′s＞reed′s＞water area′s＞farmland′s. Encountering probability of interspecies and frequency index of harriers were ranked as: hen harrier′s＞marsh harrier′s＞eastern marsh harrier′s. The regression model showed that harrier Circus numbers correlated strongly with pheasant Phasianus colchicus abundance(r2 = 0.98，P ＜0.001).The reduction of grassland area had a significant impact on the numbers of harriers perching in the grassland，however, fish net setting around the lake had a little impact on the harries appearance.