The present invention relates to a method of treating a liquid compositioncontaining lacto-N-biose, the method including: preparing a liquid compositioncontaining lacto-N-biose having a pH at 25°C of not less than 2.0 andnot more than 5.5,and heating the liquid composition at a temperature of 65°C or higher.The presentinvention can provide a treatment method that enables thermal decomposition oflacto-N-biose to be suppressed when a liquid composition containing lacto-N-biose is heated at atemperature of 65°C or higher, a liquid preparation containing lacto-N-biose that istreated using the treatment method, a dried product produced from such aliquidpreparation containing lacto-N-biose, and a method of producing a productcontaininglacto-N-biose.
