The 36-year-old man who suffered from colon cancer was accepting chemotherapy. He had high fever after bitten by mosquito when hiking on 18th September 2015 and went to ER. His Dengue Fever rapid screen was positive. He came to our OPD for paroxysmal irregular headache and whole body stabbing pain. The beastly headache affected the man and made him Chills；Fever37.4 ℃；Feeling tired；Poor appetite；Nausea after meal； Halitosis；Cold extremity. Low blood platelet count〈95000/uL〉 were noted；Yellow, dry, not even coated Fur；and the tongue was dark-red；Both were deep pulse, left pulse was slippery. The pattern of Chinese medicine differential diagnosis was Yi-li-re-du-waishu- ji-biao and Shire-zhiru-yang-ming.According to the therapeutic principle of biao-lishuang- jie,we prescribed chai-ge-jie-ji-tang and sang-ju-yin. At the 2nd visit, fever was gone within one day. Headache, Chills, Feeling tired, and GI sign has subsided lot in two days. The patient felt better generally. The coated fur turned gray and thin. The color of tongue was less dark-red. The pulse turned thin, string, and slow. However, He found some petechiae on his arm, chest, and back. Low blood platelet count and low leukocyte count appeared. Differential diagnosis that blood cell disease caused by Dengue Fever was reru- ying-xie, qi-yin-liang-xu. Then our therapeutic principle turned to qing-ying-liang-xie, yi-qi-yang-yin. He became vigor rapidly in two weeks. His white blood cell and platelet count became normal and all symptoms ameliorated. By Chinese differential diagnosis and treatment, we improved the Dengue Fever patient’s clinical symptoms quickly and recorded in detail. We hope this case report become good reference to all doctors.