A fact that the Second International Conference of Intracavitary Chemotherapy was held at Sandiego in 1988 clearly suggests that the intraperitoneal chemotherapy attracts again the attention as a new administration route aimed at complete cure and useful modality against refractory intraabdominal cancer. Basic problems (peritoneal circulation, importance of peritoneal clearance, conditions required for ip infusion and penetration depth from the tumor surface) are described. As to ip infusion of CDDP, pharmacokinetic characteristics (iv vs ip), the difference of ultrafiltrable Pt. value (chemical assay vs biological assay) and clinical notes are reviewed. Several clinical trials now on going (CDDP-STS combination, CDDP-STS-Angiotensin II, CHPP and IPCP) are introduced. Finally the future direction of intraperitoneal chemotherapy is discussed.