Investigating the cycling characteristics of dissolved inorganic carbon (DIC) in karst groundwater within arid and semi-arid regions is crucial for understanding its role in the global carbon cycle and its contribution to atmospheric carbon sinks. This study is centered on the Liulin Spring area of North China, based on sampling data from April 2019. We employed hydrogeochemical analysis and environmental isotopic tracing methods to (1) characterize the spatial distribution of DIC along the groundwater flow path; (2) elucidate the sources of HCO3-; (3) calibrate groundwater 14C ages. Results indicate that the HCO3- concentration initially increases and then decreases along the flow path, peaking in the spring discharge zone. Conversely, delta 13C values initially decrease and then increase, reaching a minimum in the discharge zone, exhibiting a negative correlation with the HCO3- concentration. The contribution of soil/biogenic CO2 dissolution to HCO3- ranges from 26% to 62%, with the highest values (56-62%) observed in recharge, runoff, and discharge zones and lower values (26-49%) observed in stagnant zones; this contribution generally decreases towards the western boundary. Calibrated 14C ages are significantly reduced and align better with expected groundwater dynamics.