The influences of additives of NH₃, HCl, KOH and CH₃OH on the solvothermal synthesis of the Zn-based metal-organic frameworks （Zn-MOF₅s） were investigated. Powder X-ray diffraction （PXRD）, thermal gravimetric analysis （TGA）, Fourier translation infrared spectroscope （FT-IR）, N₂ adsorption/desorption at 77 K and CO₂ sorption measurements were used to characterize the as-prepared Zn-MOF₅s. The experimental results show that additives of NH₃,CH₃OH,HCl and KOH in the synthesis of the Zn-MOF₅s do not change the underlying topology, but they are extremely sensitive to the pore textural properties, thus changing the CO₂ adsorption capacity. Additives would lower the pore width and the surface area,and then lower the CO₂ adsorption capacity of Zn-MOF₅s.