Abstract: AIM:o observe the dynamic changes of connective tissue growth factor (CTGF) in the pathogenic process of spontaneously hypertensive rats (SHRs) and to explore the relationship between CTGF and the development of hypertensive cardiomyopathy. METHODS: RT-PCR was used to detect the expression of CTGF mRNA in myocardial tissues. Myocardial fibrosis was detected by hematoxylin and eosin staining and the distribution of CTGF in myocardial tissues was detected by immunohistochemical staining. RESULTS: With the increase in age, left ventricular weight index, CTGF and its mRNA expression significantly increased in SHR group. The size of cardiac myocytes also increased significantly in SHR group (P<0.05). In the myocardial interstitial and vascular smooth muscle of the SHR group, a large number of brown CTGF positive particles were seen and the number was statistically significant between different age groups (P<0.01). CONCLUSION: The CTGF expression in the myocardial tissue significantly increased in different age group of SHR (from 8 weeks to 16 weeks), especially in the 16-week age group. Meanwhile, myocardial fibrosis progresses, suggesting that CTGF is involved in the occurrence and development of myocardial disease in hypertensive rats.