Stable carbon isotopes have become an important tool to advance our understanding of carbon cycle processes. The carbon isotope signature of plant-respired CO₂ (δ¹³C_R) is widely used for disentangling key physiological processes, carbon allocation, and responses to changing environmental conditions. In this review, we summarize short-term dynamics of δ¹³C_R. Plant organs differ in both their δ¹³C_R values and the magnitude of their diel variation:leaf > root > trunk and stem. Plant functional types differ in the magnitude of the diurnal shift in δ¹³C_R. The correlation between the diel variation of δ¹³C_R and the isotopic signature of the substrate is not consistent across various studies. The isotopic signature of respired CO₂ is determined by the isotope effects of photosynthetic carbon assimilation, respiratory substrate availability, the utilization of respiratory intermediates, and respiratory enzymes in connection with different carbon metabolic pathways, light enhanced dark respiration (LEDR), species-specific genetic characteristics, and changes in environmental factors. Despite recent advances in the understanding of the potential mechanisms driving short-term variation in plant δ¹³C_R, more research is required to unravel the underlying respiratory metabolic mechanisms. Stable isotope techniques have been employed in various ecological and environmental studies in China. However, not much work has been done in the field of plant δ¹³C_R and its physiological mechanisms. We hope this review will strength our understanding of the recent advances in plant δ¹³C_R research and promote the progress of in-depth research on plant respiratory metabolism in China.