Abstract: The paper aims to analyze the effect of harvest time on the juicy sac granulation of‘Guanxi pomelo’ (Citrus grandis). We selected 4 high-yield plants which were from different altitudes in the same production unit, and collected fruits at different ripening stages; then tested the quality index of fruit samples after storage. The results showed that: (1) the fruits at low altitude and were timely harvested had high quality, such as high sugar, low acid, light granulation, otherwise, the fruits quality was inferior; the single fruit quality decreased significantly with tree ages; (2) since 10/15, TSS/TA>12 and TA<1.0% marked fruit ripening; (3) the juicy sac granulation at earlier harvesting (before 10/15) significantly increased compared with that at mature harvesting (after 10/15); (4) the maturity in theory delayed by 8.4 days with 100 m increase in altitude; (5) in theory, earlier harvesting reduced production by 5.3%/10 d. The average ripening period of‘Guanxi pomelo’in Pinghe is mid- October; earlier harvesting could significantly exacerbate the juicy sac granulation rate of ‘Guanxi pomelo’stored at room temperature, and cause a loss of production.