It is shown from experiments that the stimulated Raman thresholds of the first and the second Stokes lines of CS2 are influenced by the absorption and fluorescence from the solution of β-Carotene in CS2 in liquid core optical fiber. The threshold of the first Stokes line of CS2 becomes higher when the concentration of the solution increases. And the second Stokes line of CS2 can be observed at a lower pump energy in the solution of β-Carotene in CS2 compared with that of the solution of pure CS2. Then the theoretic explanations are given and the theoretic results agree well with the experimental results.