近期暴发的新型冠状病毒肺炎（COVID-19）疫情与21 世纪以来多次暴发的新兴传染病疫情吸引了全球关注。这些新兴传染病对全球公共健康构成威胁，促生了大量针对病毒从动物到人类社会传播机制的研究。尽管已有许多研究论述了新兴传染病如何突破物种屏障和地理屏障传播的现象，但对于物种屏障和地理屏障在野生动物栖息地中存在的协同作用仍不清晰。尚未有针对病毒在生态系统中扩散、迁移和传播机制的系统性研究。为此，本文提出了生态屏障的新概念，综合了物种屏障和地理屏障概念中自然和中间宿主对病毒传播的影响，系统讨论了影响病毒突破生态屏障，实现传染病从野生动物到人群传播的多个关键影响因素，包括传播途径、接触概率、接触频率和病毒特征等。针对人类活动和全球化进程对生态屏障强度的显著影响，本文也分析了人类活动削弱生态屏障的机制，包括全球气候变化可以诱发和扩大新兴传染病的范围，人类活动可以增加病毒与人类社会的接触频率和进入人群的传播概率，全球化还会在城市中形成新的高风险区域等。本文阐明了生态屏障阻碍病毒感染人群的传播机制，相关结论为保护生态屏障、降低新兴传染病传播风险和保障公共安全提供了理论支撑。

The recent outbreak of coronavirus disease 2019 (COVID-19) and concerns about several other pandemics in the 21st century have attracted extensive global attention. These emerging infectious diseases threaten global public health and raise urgent studies on unraveling the underlying mechanisms of their transmission from animals to humans. Although numerous works have intensively discussed the cross-species and endemic barriers to the occurrence and spread of emerging infectious diseases, both types of barriers play synergistic roles in wildlife habitats. Thus far, there is still a lack of a complete understanding of viral diffusion, migration, and transmission in ecosystems from a macro perspective. In this review, we conceptualize the ecological barrier that represents the combined effects of cross-species and endemic barriers for either the natural or intermediate hosts of viruses. We comprehensively discuss the key influential factors affecting the ecological barrier against viral transmission from virus hosts in their natural habitats into human society, including transmission routes, contact probability, contact frequency, and viral characteristics. Considering the significant impacts of human activities and global industrialization on the strength of the ecological barrier, ecological barrier deterioration driven by human activities is critically analyzed for potential mechanisms. Global climate change can trigger and expand the range of emerging infectious diseases, and human disturbances promote higher contact frequency and greater transmission possibility. In addition, globalization drives more transmission routes and produces new high-risk regions in city areas. This review aims to provide a new concept for and comprehensive evidence of the ecological barrier blocking the transmission and spread of emerging infectious diseases. It also offers new insights into potential strategies to protect the ecological barrier and reduce the wide-ranging risks of emerging infectious diseases to public health.