Abstract: Semantic retrieval pivotal technique is semantic expansion。The paper makes use of the calculation formula based on the words co-occurrence model with attenuation gene to obtain relativity information resources for word and word。 Then, it concludes a complete automatic method to construct a semantic relation database used by information retrieval system。Finally，Used the constructed semantic relation database for SMART information retrieval system to realize semantic expansion。Experimental results prove the SMART information system with semantic relation database improves better retrieval efficiencies than the general one, especially，it improves consumedly query whole rates。

摘要： 语义检索的关键技术就是语义扩展。文中利用基于带衰减因子的词共现模型计算公式来获得词与词之间相关性信息资源，从而给出了用于信息检索系统中的语义关系库完整的自动构建方法。将生成的语义关系库用于SMART信息检索系统中以实现语义扩展。实验结果证明：具有语义关系库的SMART信息检索系统比原不具有语义关系库的SMART信息检索系统提高了检索效率，特别是大大地提高了查全率。