Abstract: 【Objective】 To study the relationship between seed harvesting time and seed vigor of early-maturing maize hybrids in Xinjiang seed production base in the hope of providing theoretical basis for seed production enterprises to produce high-quality seeds. 【Methods】 Early main maize varieties Xinyu 29, Xinyu 35 and Xinyu 54 in Xinjiang were chosen for hybrid seed production, after pollination every three days, they were harvested, and their grain moisture contents were determined. After the seeds were dried, maize seed vigor was evaluated by standard germination, cold test, field seedling emergence identification and relative conductivity measurement. 【Results】 There were differences in water content, standard germination rate, cold test germination rate, field emergence rate and relative electrical conductivity of maize seeds in different harvesting periods. The content of Xinyu 35 was greater than that of Xinyu 29, the conetent of Xinyu 29 was greater than that of Xinyu 54 in terms of physiological dehydration rate. The grain-filling rate of Xinyu 29 was greater than that of Xinyu 54, while that of Xinyu 54 was greater than Xinyu 35's. The seeds of Xinyu 29 were harvested 48-63 d after pollination, the standard germination rate was above 93.3%, cold test germination rate was above 92.0% and the actual seedling emergence rate was above 89.0%. The seeds of Xinyu 35 were harvested 48-63 d after pollination, the standard germination rate was above 93.3%, cold test germination rate was above 90.0% and the actual seedling emergence rate was above 89.0%. The seeds of Xinyu 54 were harvested 48-63 d after pollination, the standard germination rate was above 94.7%, cold test germination rate was above 90.0% and the actual seedling emergence rate was above 89.3%. 【Conclusion】 In the early-maturing seed production area of Xinjiang, the days after pollination can be used as a reference index to guide the field harvest of hybrid seeds, so as to obtain hybrid seeds with high vigor.