Disclosed are a biodegradable coating composition for a mulching paper and a mulching paper. Out of these, the biodegradable coating composition for mulching paper to be coated on a surface of mulching paper comprises: spring water prepared by immersing a mineral substance powder that includes sericite powder and has a particle size distribution of 400 to 700 mesh in a container containing water for 10 to 20 days and thus dissolving a mineral component of a mineral substance in water at 45 to 72 parts by weight; charcoal powder having a particle size of 1,000 to 3,000 mesh at 3 to 8 parts by weight; calcium solution at 8 to 13 parts by weight; a filler including sulfur powder, illite powder, and expanded vermiculite powder at 5 to 15 parts by weight; starch at 5 to 8 parts by weight; and an additive at 10 to 20 parts by weight.