Abstract:The content of anthrone and sulfuric acid，reaction temperature，reaction time，sample extraction time and sampling position of leaves in the classical anthrone colorimetric reaction system were optimized by using fresh leaves of young barley seedlings as experimental materials.The results showed that the optimized arthrone and sulphuric acid reaction system consists of 100 μL arthrone and 1 000 μL sulphuric acid，which subjected to color-reaction at 100℃for 7 min.The suitable time for soluble sugars extraction from barley fresh leaf in boiled water was 10 min and the upper section of the second leaf from the top was suggested to be collected as samples.This method is simple，rapid and practical，which provides an effective reference value for the rapid screening of soluble sugar indicators in plant samples.