By means of ~(29)Si and ~(27)Al magic angle spinning nuclear magnetic resonance(MAS NMR) combined with deconvolution technique, X-ray diffraction(XRD), scanning electron microscopy(SEM) as well as energy dispersive X-ray system(EDX), the effect of 5 wt% corrosive solutions( viz. 5 wt% Na_2SO_4, MgSO_4, Na_2SO_~(4+)Na Cl and Na_2SO_~(4+)Na Cl+Na_2CO_3) on C-S-H microstructure in portland cement containing 30 wt% fly ash was investigated.The results show that, in MgSO_4 solution, Mg2+ promotes the decalcification of C-S-H by SO_4~(2-),increasing silicate tetrahedra polymerization and mean chain length(MCL) of C-S-H. However, the substituting degree of Al~(3+) for Si~(4+)(Al[4]/Si) in the paste does not change evidently. Effect of Na_2SO_4 solution on C-S-H is not significantly influenced by Na Cl solution, while the MCL and Al[4]/Si of C-S-H in fly ashcement paste slightly change. However, the decalcification of C-S-H by SO_4~(2-) and CO_3~(2-) attack, as well as the activation of fly ash by SO_4~(2-) attack will increase the MCL and Al[4]/Si, which are both higher than that under Na_2SO_4 corrosion, MgSO_4 or Na_2SO_4 +Na Cl coordination corrosion. By means of Si and ~ (27) Al magic angle spinning nuclear magnetic resonance (MAS NMR) combined with deconvolution technique, X-ray diffraction (XRD), scanning electron microscopy (SEM) ray system (EDX), the effect of 5 wt% corrosive solutions on vox (5 wt% Na_2SO_4, MgSO_4, Na_2SO_ (4+) NaCl and Na_2SO_ (4+) NaCl + Na_2CO_3) on CSH microstructure in portland cement containing 30 wt% fly ash was investigated. The results show that, in MgSO_4 solution, Mg2 + promotes the decalcification of CSH by SO_4 ~ (2 -), increasing silicate tetrahedra polymerization and mean chain length (MCL) of CSH. However, the substituting The effect of Na_2SO_4 solution on CSH is not significantly affected by NaCl solution, while the MCL and (4+) (Al [4] / Si) in the paste does not change evidently. Al [4] / Si of CSH in fly ashcement paste slightly change. However, the decalcification of CSH by SO_4 ~ (2-) and CO_3 ~ (2-) attack, as well as the activation of fly as h by SO_4 ~ (2-) attack will increase the MCL and Al [4] / Si, which are both higher than that under Na_2SO_4 corrosion, MgSO_4 or Na_2SO_4 + NaCl coordination corrosion.