Abstract: Objective To understand the distribution patterns and the factors influencing the interval between entry of mainland China and diagnosis in imported COVID-19 cases in Guangdong Province to provide evidence for formulating and implementing effective control measures. Methods We collected the data of imported COVID-19 cases from March 1st to April 10th, 2020 published on the official websites of Health Commission of Guangdong Province and local government of the cities in Guangdong Province for epidemiological analysis. Descriptive statistical methods were used to analyze the distribution patterns of the interval between entry of mainland China and diagnosis of the imported cases, and multivariate logistic regression was used to analyze the factors influencing the interval. Results A total of 179 imported cases were reported in Guangdong by April 10th, 2020. The average interval between entry of mainland China and diagnosis was 4.21 days with a median of 2 days. The interval was between 1 and 3 days in 69.8% of the cases. Multivariate logistic regression analysis showed that a negative result of the initial nucleic acid test (OR=5.205, 95% CI: 1.100-24.640, P=0.038) and interval between entry of mainland China and a positive diagnosis >2 days (OR=85.654, 95%CI: 24.569-298.615, P<0.001) were risk factors for the finding delay. Conclusion The results of initial nucleic acid detection and the interval between entry of mainland China and a positive diagnosis of COVID-19 are the major contributing factors of delayed case detection. This finding suggests that strict quarantine and detection measures should be carried out for the personnel entering China to accurately and quickly identify the cases.