Groundnut (Arachis hypogaea L.) is a member of sub-family, Papilionaceae of the family Leguminosae. Groundnut is also known as peanut, mungphalli, china badam and wonder badam. Arachis hypogaea mainly two type Virginia (spreading) and Spanish (bunch). The Virginia group does not produce flowers on the central branch, only on the lateral branches. The seeds show some dormancy and the crop is relatively late maturing (130-170 days). Collar rot (Aspergillus niger Van Tiegham) of groundnut caused by Aspergillus niger has become severe and wide spread in many districts of Rajasthan state resulting in huge economic losses. An experiment was conducted during kharif seasons of 2018 to 2019 to find out some resistance sources against collar rot disease of groundnut in sick plot condition at Agricultural Research Station, Bikaner. Evaluation of forty genotypes /varieties of groundnut were revealed that none of the entries was found free or resistance from the disease. However, five genotypes /varieties were found moderately resistant (< 20%) against collar rot disease. These were Girnor-3, HNG-69, TG-37, ICMS-6 and ICMS-28. Twenty-five genotypes/varieties were found tolerant (20-40%) against collar rot disease.