A method of evaluating quality of miRNA derived from a body fluid sample includes a measuring step; comparing a measured value(s) of the abundance(s) of the one or more reference miRNAs in a body fluid sample or a representative value thereof to a measured value(s) of the abundance(s) of the one or more reference miRNAs in a standard body fluid sample or a representative value thereof, to obtain a difference(s) or a ratio(s) of the measured value(s) of the abundance(s) of the one or more reference miRNAs or the representative value thereof between the body fluid sample and the standard body fluid sample; and judging the quality of the miRNA derived from the body fluid sample based on the difference(s) or the ratio(s) of the measured value(s) of the abundance(s) of the one or more reference miRNAs or the representative value thereof obtained in the comparing step.