中文摘要：

证候的复杂性源于其高维高阶性。证候的高维性表现为构成证候系统的空间因素种类繁多，数目庞大，至少涉及病因、病机、病位、病性、病势、病理、症状、邪正关系、机体状态9类因素，每类因素中又包含若干子因素。证候的高阶性表现为证候各因素之间相互关系的复杂性。运用贝叶斯网络技术对肺系疾病中证候构成因素之间关联形式进行研究，结果表明各因素之间的联结形式非常复杂，既有线性相关，又有非线性相关，它们相互交织，形成复杂的网络结构，表现出典型的非线性特征。

英文摘要：

The complexity of syndromes in traditional Chinese medicine comes from their high dimensions and high ranks. The high-dimensional characteristics of syndromes manifest in various and numerous space elements that constitute the clinical syndrome system. The elements can be grouped into at least nine categories including pathogenesis, pathological mechanism, pathological nature, pathological situation, pathological changes, and symptoms, relationships between evil QI and healthy QI, and body state. Furthermore, each element contains several sub-elements. The high-rank characteristics of syndromes manifest in the complex relationships among the elements. Dependency relationships among the elements of the lung diseases were extensively studied using Bayesian network technology. The result shows that the dependency relationships exhibit typically complex and nonlinear characteristics, linear and nonlinear interactions among the elements lead to a complex syndrome network architecture.