The recombinant E. coli BL21(containing recombinant plasmid pGEX-SLP)was induced by IPTG to obtain recombinant fusion protein GST-SLP. This fusion protein was purified by non-specific lithium chloride precipitation and specific Pierce GST Spin Purification Kit purification method. The purified results were identified by SDS-PAGE. The results showed that the target fusion protein with the size of about 71 ku could be purified by using two methods, but the purification effect by lithium chloride precipitation...