The invention provides a novel application of a recombinant ganoderma lucidum immunological regulation protein (rLZ-8) in treating thrombopenia. In the experiments of preventing and treating the thrombopenia of rats and dogs caused by cyclophosphamide, the rLZ-8 prepared from physiological saline carries out administration on an experimental animal model with lower thrombocytes, THPO and IL-6 areused as positive medicines, continuous administration is carried out, the number of the thrombocytes in blood is detected, the changes of the number of the thrombocytes before and after therapy are contrasted, and the medicine effect is analyzed. Compared with a model group, the rLZ-8 medicine group already obviously stimulates the thrombocyte proliferation of rats, Guinea pigs and dogs in the initial period (the 3rd day to the 5th day) of the administration, the difference is very obvious, the thrombocytes are recovered to a normal level in the middle period (the 7th day to the 10th day) of the administration, and the invention also obtains a very good effect in treating the thrombopenia of a Guinea pig experimental animal model caused by injecting anti-thrombocyte serum.