This paper studied the effects of 3 pruned methods(2 stems,3 stems and 4 stems pruned method)on

photosynthetic gas exchange parameters,transpiration and distribution pattern of assimilate.The result showed that

net photosynthetic rate(Pn),stomatal conductance(Gs),stomatal limitation value(Ls),transpiration rate(Tr)and water

use efficiency(WUE)were in upper leaves>in middle leaves>in lower leaves under 3 pruned methods.In middle or lower

leaves the decrease of Pn was considered as a result of non-stomata restriction.Compared with 2 stems pruned

method,the Tr in upper or middle leaves,and WUE in lower leaves of 3 or 4 stems pruned method increased.Under 3

pruned methods,the distribution pattern of assimilate to fruits was the highest,the next was to stems and leaves,and

the distribution of assimilate to root was the lowest.Compared with 2 stems pruned method,per plant yield and weight

of single fruit of sweet pepper were significantly increased under 3 or 4 stems pruned method.