This invention provides compounds, compositions and methods for modulating the expression of human GST-π using RNA interference. The RNA interference molecules can be used in methods for preventing or treating diseases such as malignant tumor. A nucleic acid molecule can have a) a polynucleotide sense strand and a polynucleotide antisense strand； b) each strand of the molecule being from 15 to 30 nucleotides in length； c) a contiguous region of from 15 to 30 nucleotides of the antisense strand being complementary to a sequence of an mRNA encoding GST-π； and d) at least a portion of the sense strand can be complementary to at least a portion of the antisense strand, and the molecule has a duplex region of from 15 to 30 nucleotides in length.
