In several satsuma mandarin (Citrus unshiu Marc.) cultivars, the parameters of productivity (flowering, fruiting, yield, etc.) of one year correlated negatively with those of the next year, while the fruit weight and concentration of soluble solids in fruit juice of one year correlated positively with the productivity parameters of the next year. Our multiple regression analyses demonstrate that the concentration of soluble solids is an effective second factor, whereas fruit load is the main factor associated with productivity of the next year. The relation was clearer in cultivars with more variable yields. In those cultivars, the flowering intensity of the next year tended to increase in parallel with increase in the concentration of soluble solids, and the number of set fruit and yield showed similar relations at least until a concentration of about 12% soluble solids. These findings indicate that the concentration of soluble solids is a useful parameter for estimating the productivity of the next year and appropriately high fruit quality might correlate with high productivity.