The cellular energy derives mainly from glycolysis and mitochondrial oxidation, and cellular activity correlates closely with energy status. Cancer cells have much higher rate of glucose uptake and increased glycolysis, produce high levels of lactate. Current advances in bioenergy metabolic mechanism of cancer were expounded. With intense investigation in this field combined development of metabolic imaging techniques, it will benefit unveiling the causal relationship between metabolic alteration and progress of cancer and be harnessed therapeutically.