Abstract: Changes in acid invertase (EC3.2.1.26), fructanase (EC3.2.1.7) activities and sugar distribution were investigated in the different portions of asparagus (Asparagus officinalis. L. cv. E414, HC, WC and S-235, grown in greenhouse) spears harvested in "Spring harvest (2nd and 3rd of March)", "Middle harvest (27th and 29th of May)" and "Summer harvest (27th of August)". The weight of "Middle harvest" asparagus was apt to be higher than "Spring harvest" and "Summer harvest". In soluble and cell wall-bound fractions, the acid invertase and fructanase activities of the two spears increased in the "Middle harvest" concurrent with the most rapid increased in reducing sugar content but with a lower sucrose and fructane contents. In the top portion of ‘HC’, substrate of sucrose was negatively correlated with acid invertase activity in soluble fraction and accounted well for the relation between the substrate and the activity. Due to the existence of fructane in the spear, fructose content was considered to be higher than glucose content. The best harvest time was in the "Middle harvest" since the total sugar content and fresh weight were adequate.