介绍了基于单根碳纳米管的纳米分子秤系统 ,以及其测量分子 (团 )质量的基本原理 ,建立了适用于该系统的纳米悬臂梁模型 ,通过求解系统的振动方程 ,研究了系统的固有频率与分子 (团 )质量之间的关系 ,用数值法计算了两者的函数曲线 .结果表明 ,碳纳米管可以直接测量fg级的分子(团 )质量 ,当分子 (团 )质量超过碳纳米管自身质量时 ,纳米分子秤变得不够灵敏 . In this paper, we introduce the nanometer scale system based on single carbon nanotubes and the basic principle of measuring the mass of the molecules. We established a model of the cantilever beam that is suitable for this system. By solving the vibration equation of the system, Frequency and molecular (mass) mass, the function curves of the two are calculated numerically.The results show that the carbon nanotubes can directly measure the molecular mass of fg grade, When the quality of the tube itself, the nanometer scale becomes less sensitive.