The present experiment was undertaken in Kharif 2013 at Upland Rice Research Block of S. G. College and Research Station, Jagdalpur to investigate the role of floral behavior on yield physiology of upland rainfed rice. Spikelet fertility is found to be positively linked with prolonged vegetative growth (0.0255) because of ample supply of food material. Plant height was observed to be very important in operating grain yield via panicle length (0.2518), spikelet per panicle (0.2821*), spikelet fertility (0.5058**) and biological yield (0.3972**). Grain yield was positively and significantly associated with total crop biomass (0.6669**), plant height (0.5059**). Days to 50 percent flowering was positively associated with crop duration (0.7451***) but exhibited negative inheritance with grain yield (-0.1941) which may pertain to post anthesis stress. Summarily, floral biology should be emphasized while designing crop breeding experiment and genotypes exhibiting positive inheritance among these traits with grain yield must be opted to precede rainfed rice research.