Bovine respiratory disease complex （BRDC） is one of the most important infectious diseases that endangers domestic and international cattle industry.The etiological factors include multiple pathogens such as viruses，bacteria，mycoplasmas，as well as various stressors.Clinical diagnosis is preliminarily drawn by observing the abnormal signs such as dyspnea and the accuracy of pathogen diagnosis is low.Furthermore，because the disease has the characteristics of multi-etiologic mixed infection，the laboratorial diagnosis is often not specific，which makes it difficult to judge the therapeutic effect and prognosis of the disease.In order to provide reference for early and accurate diagnosis，timely treatment and effective prevention and control of BRDC，this paper outlined the etiology，epidemiology，hazards，and diagnostic methods of BRDC，including both conventional clinical and molecular biological diagnostics，as well as new methods based on host biomarkers such as acute phase proteins，stress-related hormones，and transcriptomic diagnosis.Further，the practical application，advantages and disadvantages of these methods were briefly described，and the future direction of diagnostic methods and the problems to be solved were also prospected.