Objective　To　investigate　the　role　of　angiotensin　I　receptor　type　2　(AT2)　on　collagen　metabolism　in　cardiac　fibroblast,　and　the　difference　between　AT2　and　angiotensin　I　receptors　type　1(AT1).　Methods　Adult　rat　cardiac　fibroblasts　were　isolated　and　cultured.　The　cells　were　divided　into　4　groups:　Angiotensin　II　(Ang　II　),　Ang　II　+Losartan,　Ang　II　+PD123319,　Ang　II　+　Losartan　+　PD123319.　Semiquantitative　reverse　transcription　PCR　was　used　to　determine　the　mRNA　levels　of　collagen　1　(Col　1)　and　tissue　inhibitor　of　metalloproteinase　1　(TIMP-1).　Results　Losartan-treatment　making　ATI　blockade　decreased　Col　I　mRNA　to　71.8%　in　cardiac　fibroblasts,　AT2　blockade　from　PD123319-treatment　decreased　Col　I　mRNA　to　81.　5%.　co-treatment　of　both　ATI　and　AT2　blockade　decreased　Col　I　mRNA　to　50.　9%)　the　ATI　blockade　with　Losartan-treatment　decreased　TIMP-1　mRNA　to　88.　1%　in　cardiac　fibroblasts,　AT2　blockade　by　PD123319treatment　decreased　TIMP-1　mRNA　to　75.　A%,　Both　ATI　and　AT2　blockade　by　co-treatment　decreased　TIMP-1　mRNA　to　44.1　%.　Conclusion　AT2　receptor　is　involved　in　collagen　metabolism　in　cardiac　fibroblast　by　regulating　the　levels　of　Col　I　and　TIMP-1　mRNA.