Abstract: In Burkina Faso, information about composts’ role in greenhouse gas reducing is scarce. This study assessed six urban composts application effects on soil carbon storage in sorghum three-year experiment. Composts were applied at 3 t DM ha-1 year1 rate, single or combined with 50 t ha-1 year-1 urea rate. Soil properties were analyzed with soil sampled in the early 20 cm of soil. The treatments were compared to a control without any fertilization and a 50 t ha-1 year-1 urea treatment. Comparisons were also done between single composts treatments and composts combined with 50 t ha-1 urea ones. In comparison to the control, single or combined with urea composts application improved soil bulk density, fine soil rate and organic carbon contents. Single composts treatments carbon storage ranging from 8.76 to 11.58 t ha-1 were not significantly different from the control. However, when composts were combined with urea, carbon storage ranged from 8.42 to 13.07 t ha-1 and was significantly increased by comparison to the control. Best composts seemed to be those produced with various and balanced composting materials. Eco-friendly urban waste composts adoption could improve soil fertility and mitigate greenhouse gas emission. Keywords: urban wastes composts, soil fertility, greenhouse effect, Burkina Faso