Cytoloxic effects of hyperthermia combined with DDP on MKN28 and MKN45 cells were studied by MTT assay according to a nested design. The results showed: hyperthermia alone above 43 °C for 30 mins was cytotoxic; hyperlhermia at temperature lower than 43 °C for 30 mins could increase sensitivity of cancer cells to DDP. The cytoloxic effect of simultaneous use of hyperthermia and DDP was more marked than that of sequential use of the 2 treatments. Hyperthermia combined with DDP could inhibit growth of human gastric adenocarcinoma cells regardless of their degree of differentiation.