The invention belongs to field of biotechnology, specifically, in order to lead to the difference of increased secretion level, without will affect its biological function based on single mutation introducing coding mankind IL-2, and the mutain thus derived from is imported. Particularly, these mutation are to be located at human IL-2 in the primary series of position 35 based on non-conservative change amino acid, preferably replacement K35E, K35D and K35Q. The present invention also relates to for obtaining two expression system recombinant human il-2s, and the mutain that thus derives from uses method described in the present invention. The above method can be used for improving the production efficiency of human IL-2, and the two mutain thus derived from is in laboratory and commercial scale. It can be used for the T cell of therapeutic purposes and amplification in vitro for adoptive transfer therapy using the protein that this method obtains.
