Abstract: The development of nanotechnology faces great challenges of uncertainty. Under the condition of uncertainty， the assessment of nanotechnology might be confronted with Collingridges dilemma. Based on the traditional technological assessment， scholars in Europe and USA proposed three approaches—vision assessment， constructive assessment and real-time assessment. However， such technological assessment models have their own limitations such as trying to predict the future of nanotechnology and controlling the directions of nanotechnology development. Based on the Chinese philosophy， the feasibility assessment of nanotechnology is action-oriented and characterized by in situ (acting according to circumstances)， dynamics (instantaneity and advance with the times) and integrality. Faced with the uncertainty of nanotechnology， the feasibility assessment of nanotechnology emphasizes the coexistence with uncertainty rather than avoiding or controlling it， which is of significance to tackle Collingridges dilemma.

Key words: nanotechnology, uncertainty, technology assessment, feasibility