Abstract： This article elucidates Professor YU Shangzhen's clinical experience in treating cerebral edema using theory of "when blood fails to move， it transforms into water." Professor YU considers this principle fundamental to cerebral edema treatment， advocating blood-invigorating， stasis-resolving， and water-draining methods. Syndrome differentiation based on this theory classifies cerebral edema into four main types： pathogenic qi stagnation and constraint with blood stasis-water retention syndrome，phlegm-heat fu-organ excess with blood stasis-water retention syndrome， spleen-stomach deficiency with blood stasis-water retention syndrome， and kidney qi insufficiency with blood stasis-water retention syndrome.