The purposes of this research are to review the current economic measures to be used to assess the economic effects of agricultural infrastructure projects, to find some effects not included into the current measures, and to suggest new additional economic measures. So thus, economic assessment for agricultural infrastructure projects has been criticized to be overestimated. For example, some research reported that the projects enhanced rice productivity by 20% or 30%. We suggest four new measures to evaluate economic effects of agricultural infrastructure projects: (1) enhancement in productivity, (2) switchover from low-income crops to high-income crops, (3) rises in land price, and (4) lower fluctuation in production.