Objective·To explore the difference in marginal accuracy between cobalt-chromium basal crowns produced by selective laser melting (SLM) and casting in clinical application. Methods·Twenty plaster casts for 20 clinical teeth that were prepared according to the standard of full crown were produced. Twenty SLM cobalt-chromium basal crowns and 20 casting cobalt-chromium basal crowns were produced and placed on plaster casts. A stereomicroscope was used to observe the marginal gap pattern between basal crowns produced with silicon rubber replication technology and plaster casts, and measure the marginal gap widths. Finally, average values of two groups were calculated and compared. Results·The average marginal gap widths of SLM cobalt-chromium basal crowns and casting cobalt-chromium basal crowns were (60.39±10.63) μm and (91.41±37.68) μm, respectively. The former was significant smaller than the latter (P=0.000). Conclusion·SLM cobalt-chromium basal crowns have a much high marginal accuracy and a better clinical restoration effect than casting cobalt-chromium basal crowns.