The Tarim River Water Resources Reallocation Project is specified because of the inland geographical aridity situation. The objective of this project in short-term is to solve the problem of unbalanced allocation of ecological water and to keep ecological safety of the whole valley. Here are three basic problems on the water resource space-time allocation. The first is the allocation of water quantity in longitudinal and transverse direction. The second is the structure of water usage quota for each section of the river valley. The last is the process control of the quota. According to the principle that social development should be based on ecological safety, the disposal of the water quota in a region should be started with restricting ecological water and the method of discharging deduction should be adopted so that water usage in a region is based on rigid restrictions. Water quota is a system associating with the quantity control and structure control of the water usage. The process control of water quota should be based on the principal that the quota should be increased when incoming flow is abundant and decreased when short. To distribute water quota, period choice and year-inner apportionment are other essential and practical problems.