Objective  The physiological and biochemical properties of Myrica rubra cv. Shuijingzhong fruits during development were studied.

  Method  Indicators, including color, individual weight, dimensions, shape, TSS, and contents of soluble sugars and organic acids, of the fruits were determined in 18 consecutive days for the analysis.

  Results  During the developmental stages, the fruit color changed slowly with increasing L^* till reaching a constant and from a negative to a positive a^*/b^* ratio. The weight, length, and girth of the fruit all on an increasing trend as it grew. The contents of TSS, fructose, and glucose accumulated rapidly to peak at maturation. Malic acid increased initially followed by a decline and another increase, while citric acid and oxalic acid declined continuously. The L^* and a^*/b^* of the fruits significantly correlated with TSS and sucrose contents, but inversely correlated with oxalic acid. The weight, length, and girth of a fruit significantly correlated with TSS, fructose, glucose, and sucrose contents, while significantly inversely correlated with citric acid and oxalic acid.

  Conclusion  The color differences (L^* and a^*/b^*) and quality indices (e.g., individual weight, length, and girth) closely related to the intrinsic properties of the fruits. Therefore, these external measurements reflected the fruit development and could be applied to determine the appropriate timing for harvest.