Late leaf spot (LLS) cause substantial yield losses and reduce the fodder and seed quality in groundnut (Arachis hypogaea L.). Knowledge on components of resistance to these diseases should facilitate the development of groundnut cultivars with enhanced resistance to LLS. The present investigation was performed to study the biochemical characterization of late leaf spot resistant groundnut genotypes viz., RHRG 6083, GPBD 4, KDG 128, ICG 11426, ICG 12672, ICG 13919, ICG 14475, ICGV 94118, ICGV 13160, ICGV 13165 including two wild species ICGV 13160 (Arachis batizocoi) and ICGV 13165 (A. cardenasi) and two susceptible viz., SB XI and JL 24 at AICRP on groundnut, MPKV, Rahuri during 2013-14 and 2014-15. The content of phenol and the enzyme activity of peroxidase and polyphenol oxidase was found more in resistant than susceptible genotypes, while total sugar content was found to be maximum in susceptible than resistant genotypes. There was reduction in reducing sugar content, while total sugar and total phenol and the enzyme activity of peroxidase and polyphenol oxidase was increased after inoculation of the pathogen in all groundnut genotypes. The reduction level of these biochemical constituents was less in resistant genotypes. Similarly, increased level of total sugar, total phenol, and peroxidase and polyphenol oxidase activity was more in resistant genotypes than susceptible genotypes.