Abstract: The present invention relates to a Streptococcus pneumoniae antiserum without cross-reactivity and method for producing the same, more specifically, it relates to a method for producing a S. pneumoniae antiserum comprising the step of removing cross-reactivity using S. pneumoniae and a S. pneumoniae antiserum prepared by the method. The Streptococcus pneumoniae antiserum prepared according to the method of the present invention has very high specificity for a particular serotype, since the cross-reactivity with S. pneumoniae of serotypes expressing capsular polysaccharides of similar structure is removed. Therefore, it can be very useful in the related art that requires accurate quantification of S. pneumoniae capsular polysaccharide.