[Penelitian ini bertujuan menganalisis pengaruh warna komposit resin nanoaktivasi sinar terhadap temperatur di permukaan dasar. Spesimen berupa kompositresin warna terang (B1), sedang (A3), dan gelap (C3) dari Filtek Z350XT (3MESPE,USA). Uji temperatur dilakukan di permukaan dasar spesimen pada saatdilakukan penyinaran menggunakan light curing unit. Terdapat perbedaantemperatur permukaan dasar antara komposit resin warna B1 dan A3 (p<0,05),warna A3 dan C3 (p<0,05), serta warna B1 dan C3 (p<0,001). Disimpulkan,warna komposit resin mempengaruhi temperatur permukaan dasar., The objective of the present study was to analyse the effect of light-curednanofilled resin composite shades on their undersurface temperature. Specimensare lighter shade (B1), darker shade (C3), and middle shade (A3) of light-curednanofilled resin composites (Filtek Z350XT, 3M-ESPE, USA). Temperaturemeasurement was conducted on the undersurface of specimens when cured usinga light curing unit. It was shown that there are temperature differences betweenthe composites of B1 and A3 (p<0,05), A3 and C3 (p<0,05), as well as B1 and C3(p<0,001). In conclusion, shade of light-cured nanofilled resin compositesinfluenced their undersurface temperature.]