Cardiac fibroblasts (CFs), one of the major groups of cardiac cells, play a prominent role in the cardiac microenvironment through communicating with other cells such as cardiomyocytes, endothelial cells and immune cells. These communications are required not only during cardiac development but also during pathogenesis. CFs are also involved in developmental changes in the post-natal and pre-natal heart through depositing extra cellular matrix (ECM) and maintaining cardiac tissue structure. Furthermore, CFs show both detrimental and beneficial effects in maintenance of the electrophysiology of the heart. Senescent CFs in the cardiac microenvironment influence other cardiac cells through paracrine signaling, which would worsen or cure the diseases. Therefore, there is a need of exclusive study on CFs’ role in the developmental stage of the heart, electrophysiology, and senescence. This review discusses the current research about CFs’ function, especially the CFs’ role in cardiac development, electrophysiology, and senescence, and proposes a certain gap filling future prospective.