Rho family proteins are small G proteins with GTPases, which are widely presented in eukaryotic tissues. RhoA (Ras homologous gene family member A) is one of the most critical Rho family members. RhoA serves as a molecular switch that cyclically regulates intracellular signalling between an inactive GDP binding conformation and an active GTP binding conformation. Rho‐kinase 1 (Rho‐related coiled‐coil containing protein kinase, ROCK1) is the direct downstream and primary effector substrate of RhoA. Phosphorylation of myosin phosphatase targeting subunit 1 (MYPT1), one of the important physiological substrates of ROCK1, facilitates interaction and phosphorylation of the catalytic domain of ROCK1. The RhoA/ROCK signal mediates the process of cardiovascular diseases by regulating biological processes such as inflammation, differentiation and apoptosis. In addition, some research suggested the RhoA/ROCK1 pathway regulates mitochondrial fragmentation through Drp1, a large GTPase, which is activated and transported to the surface of mitochondria to regulate mitochondrial fission. Shen et al. found that RhoA/ROCK1 pathway was engaged in phosphorylated Drp1 at the 616th Serine in cardiomyocytes pretreated with TNF‐α, which promoted mitochondrial fragmentation. Another report showed that in LPS‐pretreated mice, ROCK1 inhibitor could improve mitochondrial function by restricting excessive mitochondrial fission through inhibiting Drp1(Ser616) phosphorylation.