Yeast-like fungus is widely distributed in nature. It infests in all parts of human body as normal flora. While one's immunity lows down, it will endogenous or prone to opportunistic infections. As to the widely misuse of antibiotics and immunosuppressants in these years and the popularity of organ transplantation and catheter technology, prevalence rate and death rate of opportunistic fungal infection are rapidly rising up. Candida has become the fourth pathogen in blood infection. Rapid identification plays an important role in the fungus’ diagnosis and treatment.