Abstract: It is an object of the present invention to provide a method for preparing a cRNA, the method being capable of preventing decrease in cRNA yield. In order to achieve the object, the method comprises (a) a step of performing a reaction for preparing a single-stranded cDNA by treating with RNaseH an mRNA-cDNA hybrid prepared by reverse transcription and a reaction for preparing a double-stranded cDNA from the single-stranded cDNA and then inactivating the RNaseH contained in the resultant reaction solution; (b) a step of contacting the reaction solution with a solid support having a cationic group on its surface under pH conditions where the cationic group is positively charged; (c) a step of separating the solid support from the reaction solution; (d) a step of eluting the double-stranded cDNA from the solid support; and (e) a step of performing a transcription reaction for preparing a cRNA from the double-stranded cDNA.