Taking the winter-spring season cucumber seedlings in the solar greenhouse as experimental
material，this paper studied the effects of different supplementary light intensities on the quality of cucumber seedlings．
The results showed that the light treatment could effectively reduce the seedling hypocotyl length and plant height，
but significantly increase the stem diameter，leaf area，specific leaf weight，dry matter content，and strong seedling
index．Moreover，supplementary light could facilitate the distribution of dry matter to leaves and roots，while restrain
to stems．In addition，the contents of chlorophyll，carotenoid and starch in seedlings under supplemented light were
higher than those of the control，but the soluble sugar content was lower than that of the control．Taking the strong
seedling index as criterion of good and bad supplementary treatment，it could be seen that T（100），T（150），and
T（200） treatments were significantly superior to the control and T（50）treatment．Thinking comprehensively from
the aspects of economy and energy-saving，we recommend supplementary light intensity as 100 μmol·m^-2·s^-1．