Hydrate-based technology is a promising method for gas separation and seawater desalination. There is little information about the combination of the two applications. The CO2 hydrate formation and dissociation in saline water (3 wt sodium chloride) and deionized water in a silica gel fitted vessel are experimentally investigated by using a magnetic resonance imaging (MRI)-based pool measurement system. Three experimental cases were conducted with different procedures. MM images and mean intensity (MI) were obtained using a spin echo multislice pulse sequence. From this study, it is found that the hydrate formation in saline solution is rapid compared to that in deionized water. It is caused by the "structure making" of ions. Hydrate is formed more rapidly in the flowing process than in the cooling process due to the additional mechanical effect. The so-called "memory effect" was identified for the hydrate dissociated solution, for which the nondissociated hydrate crystals exist. It shows that the twice displacement is superior for experimental stability. Additionally, MR images show that the rapidly formed hydrate can cause blockages of the experimental loop. The sensitivity of the MM system is high when the temperature is above 284.15 K. This causes a rapid decrease in the MI as the temperature increases.