To study the effect of straw returning on composition of soil water-soluble carbon, the fluorescence spectral characteristics of WSOCwith depth were researched onland meadows with continuous no-tillage, shallow turning, deep turning and no-till cover, shallow and deep straw returning methods, and the results showed that the WSOC was all resolved two types of three fluorescent components in 0～50 cm soil layer with 3 kinds of tillage and corresponding straw returning, namely humus-like components C1 (240/400 nm) and C2 (245, 400/465 nm) and protein-like component C3 (220, 275/325 nm). Regardless of shallow or deep returning, the sequence was C1>C2>C3 in 0～20 cm topsoil, butthe change of C3 composition in 20～30 cm soil layer was negatively correlated with C1 and C2 components. It was also founded that the content of C3 component in 30～50 cm soil layer was increased with continuous straw returning. Fluorescence index analysis showed that the WSOC composition is a mixture of non-biological sources and biological sources, which indicated that the heterogeneous characteristics of the soil layer was obvious in 10～20 cm soil. For the reason of no disturbance to the soil in whole growing season with no-tillage and no-tillage straw cover, the self-generated characteristics in 20～50 cm soil layer was much strong. The ratio of C2/C1 in the 40～50 cm soil layer of straw deep returning was higher than that of shallow tillage and straw cover, indicating that thetenth of humus production and accumulation would be increased.