Based on the theory of 'spleen governing the containment of blood' in The Classic of Difficult Issues （《难经》）， it is proposed that medication toxicity damaging the middle jiao （焦） and failure of the spleen to contain blood constitute the core pathogenesis of cancer therapy induced thrombocytopenia （CTIT）. It is believed that the anti-tumor drug toxicity directly hits middle jiao， leading to spleen qi depletion， impairment of transportation and transformation， and insufficiency of the source of blood production. Consequently， the vessels and collaterals are deprived of nourishment and become structurally damaged. Blood fails to be contained and stored within the vessels， resulting in extravasation beyond the vascular system. Persistent retention of drug toxicity may further cause stasis due to blood deviating from its normal pathway and gradually consume the essence. In view of this root deficiency with branch excess， it is proposed that the treatment should focus on fortifying spleen， boosting qi and containing blood， with the aim of restoring spleen and stomach transportation functions， repairing vascular damage， and recovering the spleen's blood-containing function. According to individual syndrome patterns， prescriptions may be supplemented with herbs that stabilize vessels and consolidate collaterals， remove stasis and promote regeneration， and replenish essence and nourish marrow， providing new perspectives for the prevention and treatment of CTIT with traditional Chinese medicine.