The present study was undertaken to find out fasting total plasma cholesterol levels of SHR at different phases(labile, established and malignant) in the course of hypertension development and also to investigate effect of nicotine on plasma cholesterol levels of these animals. In nicotine administered group, 2.18 mg/kg nicotine was given daily for six weeks. The results obtained are as follows; 1) Mean total plasma cholesterol levels of SHR at labile, established and malignant phases were 104.6±3.1 mg/dlThe present study was undertaken to find out fasting total plasma cholesterol levels of SHR at different phases(labile, established and malignant) in the course of hypertension development and also to investigate effect of nicotine on plasma cholesterol levels of these animals. In nicotine administered group, 2.18 mg/kg nicotine was given daily for six weeks. The results obtained are as follows; 1) Mean total plasma cholesterol levels of SHR at labile, established and malignant phases were 104.6±3.1 mg/dl, 120.8±2.6 mg/dl and 136.6±2.5 mg/dl respectively. The total plasma cholesterol level generally increased with age of experimental animals. 2) After administration of nicotine (2.18 mg/kg/day) for six weeks, mean total plasma cholesterol levels of SHR at labile, established and malignant phases were 130.2±3.1 mg/dl, 150.4±3.3 mg/dl and 166.6±3.2 mg/dl, respectively. The result of present study strongly suggests that nicotine has a positive relationship with plasma cholesterol levels in SHR. , 120.8±2.6 mg/dl and 136.6±2.5 mg/dl respectively. The total plasma cholesterol level generally increased with age of experimental animals. 2) After administration of nicotine (2.18 mg/kg/day) for six weeks, mean total plasma cholesterol levels of SHR at labile, established and malignant phases were 130.2±3.1 mg/dl, 150.4±3.3 mg/dl and 166.6±3.2 mg/dl, respectively. The result of present study strongly suggests that nicotine has a positive relationship with plasma cholesterol levels in SHR.