Two cultivars ZD958 and DH661 were used to analyze the effect of different planting densities (45 000 plant ha–1, 75 000 plant ha?1, 10 5000 plant ha?1) on kernel development and barrenness in maize (Zea mays L.). The results showed that increasing plant density had little effects on the time of ear primordia differentiation (the ear primordia presented at 28–29 days after sowing under different densities) and the total number of floret primordia during silking. However, the differentiation of ear was postponed under high density, the number of abortive florets and unfertilized florets increased with the increase of plant density. Compared with low-density, the high density reduced number of normal florets per ear by 100.0 for DH661 and by 76.4 for ZD958. Additionally, the anthesis-silking interval (ASI) was elongated, the ratio of the silked-plants was decreased (ratio of DH661 was 93.64% and that of ZD958 was 81.80% under high density), the time of silking was delayed, the number of silked florets per ear was reduced and the pollen shedding duration was shortened with increasing plant density, which results in the increment of abortion after fertilization. Interestingly, kernel abortion would also occur during grain-filling, especially in 10 days after anthesis. The kernel number per ear had a positive correlation with the bottom transmittance at silking, 10 d after silking and 20 d after silking, while the ratio of abortive floret was negatively correlated with the bottom transmittance before flowering significantly.