Abstract: To study the mechanism of grafting affecting bloom on fruit surface of cucumber，rootstocks with significant different effects on bloom formation were used to investigate the plant growth and silicon distribution of grafted cucumber，the results showed that at fruiting stage，the plant height，leaf number and early yield of cucumber grafted on light-bloom rootstocks were lower than those grafted on heavy-bloom or medium-bloom rootstocks，but higher than own-root cucumber；There was more silicon in leaves than in stem and roots of cucumber；The silicon levels in leaves and stem of cucumber grafted on light-bloom rootstocks were lower than those grafted on heavy-bloom or medium-bloom rootstocks，as well as own-root cucumber；The roots of cucumber grafted on‘Yunnan Figleaf Gourd’showed the highest silicon content；With the growth of fruits，the silicon content increased first，and then decreased，however，the silicon content in leaves at same node gradually reduced；The silicon contents in fruits of cucumber grafted on light-bloom rootstocks were obviously lower than those grafted on heavy-bloom and medium-bloom rootstocks，as well as own-root cucumber. Different bloom-type rootstocks affected the formation of fruit bloom，which was partly associated with the absorption and distribution of silicon.

Key words: cucumber, grafting, rootstock, bloom, silicon