To provide a highly-sensitive and speedy method and a kit for measuring hyaluronic acids.

A complex having the structure of [CD44-hyaluronic acid- hyaluronic acid-bonding protein or CD44] is formed by bringing a sample containing hyaluronic acids into contact with hyaluronic acid-bonding protein marked with CD44 and a marking substance or CD44. And hyaluronic acids in the sample is measured by detecting the marking substance in the above- mentioned complex. Or by bringing the sample containing hyaluronic acids into contact with hyaluronic acids marked with a marking substance and CD44, a complex with the hyaluronic acids marked with the marking substance and CD44 is formed. And, hyaluronic acids in the sample is measured by detecting the marking substance in this complex.