采用二维正方形格点模型 ,用完全计算法研究了蛋白质分子的热力学性质 .发现体系的配分函数 Z与链长 N存在关系 :ln Z=a N + b,其中 a,b仅与温度、相互作用有关 .总简并度 g0 (m)与链长 N存在关系 :g0 (m) =a· γN ,其中 a=0 .0 9,γ=2 .72 .同时计算了蛋白质分子在自然状态构象间的平均距离 ,发现当链长 N较大时 ,平均距离趋于 1.6 7.这为研究真实蛋白质分子的热力学性质提供了一种模型和方法 Using the two-dimensional square lattice model, the thermodynamic properties of the protein molecules are studied by the full calculation method. It is found that the partition function Z of the system has a relationship with the chain length N: ln Z = a N + b, where a and b are only related to temperature, The relationship between total degeneracy g0 (m) and chain length N is as follows: g0 (m) = a · γN, where a = 0.90 and γ = 2.72.At the same time, And found that when the chain length N is larger, the average distance tends to be 1.6 7. This provides a model and method for studying the thermodynamic properties of real protein molecules