Abstract: Pim-3, a new member of the the proto-oncogene pim family which expresses serine and threonine kinase activity, shows a high similar to pim-1 and pim-2 at the function, structure and sequence. Pim-3 plays an important regulative role in the cell cycle transform, cell apoptosis and occurrence of the malignant tumors by phosphorylating numerous specific substrates.