Objective To establish the basic parameters for exposure assessment of contact materials for nut-seed food in China. Methods The contact area method was used to study the contact materials of nut-seed food in this study. Based on the contact area values, ratio of contact areas and unit mass were obtained. Results Through investigation and analysis, 114 kinds of nut-seed food were sampled, and 3 648 related data were obtained. Food contact materials of nut-seed food on the market mainly included aluminum, polyethylene, polyethylene terephthalate, polypropylene, polystyrene and coating. The average contact area per unit mass or volume(S/V)was 21.29 dm²/kg, the median was 13.40 dm²/kg, P5 was 1.11 dm²/kg, and P95 was 67.46 dm²/kg. Conclusion The basic parameters of nut-seed food contact materials could provide data support for the safety assessment in China.