Aim To investigate the dynamic changes of adrenomedullin and its specific receptors sys tem-calcitonin receptor like receptor (CRLR) mRNA expression in the stress-induced-hypertensive rats. Methods Distribute 48 rats to control group with 18 of them and stress group with 30 of the total randomly. Inflict noise or noise with eletric foot shock upon the stress group. Excute all the rats and then separate their hypothalamus to isolate the total RNA indiridually at stress 1,5, 10 and 15 days and poststress 5 and 10 days. Determine the changes of adrenomedullin and calcitonin receptor-like receptor mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR) . Results Compared with control group at the same time point, ADM and CRLR mRNA expression in the hypothalamus upregulated within foot-shock and sound stress 10 days (stress 5 days: ADM mRNA expression 0.92 ± 0.04 vs 0.99 ± 0.05, p< 0.05; stress 10 days: 1.26 ± 0.04 vs 0.92 ± 0.04, P<0. 01, and then downregulated, but still kept at a high level at stress 15 days (1.00 ± 0.04 vs 0.92 ± 0.04, P< 0.05) and posts tress 5 days ( P> 0.05) . Conclusion According to the results described above, at the gene level, the expression of ADM and its specific receptor components CRLR mRNA had changed to some degree in the process of chronic stress-induced-hyperten sion, indicating that ADM and its specific receptor maybe involve in the stress-induced-hypertension.