Non-professional groups, consisting of members gathering together out of the same hobby, have long been deemed as auxiliary power in the inheritance of intangible cultural heritage (ICH). Being widely considered as less important than professional groups, non-professional ones seem to mostly function like governments, IGOs, NGOs, among other things, to indirectly help professionals inherit ICH almost by practicing this heritage as a way of dissemination to build a better social environment friendly towards ICH to live well. However, their role in the direct and faithful inheritance of ICH can be underestimated, or even ignored. In this paper, China’s Kunqu Opera is taken as an example, one professional group (Shanghai Kunqu Opera Troupe) and one non-professional group (Shanghai Kunqu Study Society) are chosen to do some comparative analyses in pronunciation, melody, literary form of lyrics, and performing scenes of this art. It is concluded that even though not living off this art, non-professional groups could inherit some traditional factors of Kunqu Opera to a larger degree than professional ones, especially in pronunciation and melody. And one major reason can be summarized that non-professional groups, who cherish the art’s tradition heavily, don’t need to cater to the mass-market and most modern audience, who are highly influenced by modernization and globalization so that they can preserve these traditional factors carefully by studying, practicing as well as imparting them to other amateurs seriously. Thus, paying more attention to their role in the inheritance of ICH is not only sensible but also essential.