A shell-forming composition for a soft capsule comprising a non-gelatin component as the chief component, wherein the shell-forming composition is able to inhibit a decrease in physical strength (breaking strength) of the capsule when a phospholipid-containing oil with a phospholipid concentration of 20% or more by mass is used as the core of the capsule. The shell-forming composition for the soft capsule comprises (A) starch and/or dextrin, (B) a gelatinizer, (C) glycerin and (D) sorbitol, and the mass ratio of (C) glycerin:(D) sorbitol ranges from 100:30 to 100:120.