To obtain a flame-retardant composition excellent in flame retardance and abrasion resistance and capable of readily coloring, and a flame-retardant wire.

This composition is obtained by adding 20-100 pts.wt. phosphate condensate and a nitrogen-containing organic compound to 100 pts.wt. polyethylene having ≥0.94 density and ≥5 ratio of weight average polymerization degree to number-average polymerization degree and the composition has ≥0.5 and <2 content of nitrogen and phosphorus. The flame-retardant wire is obtained by using this flame retardant composition as a coating material.