In the present paper, the best experimental conditions for producinghydrates in the NaCl-H2O and MgCl2-H2O systems were found through the cryogenicRaman spectroscopy. This experimental condition is rapidly cooling to -180 ℃ andslowly warming to observe hydrate formation process (that is manifested as adarkening of the vision in the microscope), and finally, rapidly cooling down to-180 ℃. Moreover, a qualitative or semiquantitative analytical method for NaCl-MgCl2-H2O system was established. This method is that 3 537 cm-1 may instruct theexistence of NaCl hydrates, 3 514 cm-1 may instruct the existence of MgCl2hydrates, and comparison of the intensity of 3 537 and 3 514 cm-1 peaks can beused to estimate the ratio of NaCl and MgCl2 in the system. All these are thefoundations for quantifying the components of natural fluid inclusions. Theauthor supports Samson’s idea through observing the phenomenon of experiments inthe controversy of the meta-stable eutectics formation model, that is ice formson initial cooling, leaving a residual, interstitial, hypersaline liquid. Onwarming, the salt hydrates crystallize from this liquid.systems; Low temperature; Raman spectroscopy技部(973计划)项目(2002CB412605)资助