【Aim】 Spodoptera frugiperda is a major migratory agricultural pest that is native to the tropical and subtropical regions of the Americas. Hainan is one of the source areas of this pest for migration in China. Revealing the biotypes and genetic characteristics of S. frugiperda in Hainan will be beneficial for monitoring and prevention of this pest in Hainan and even China. 【Method】 Two molecular markers, the mitochondrial gene COⅠ and the nuclear gene Tpi, were used for identification and genetic characterization of 76 samples from corn plants in Hainan. 【Result】 According to COⅠ sequences, 76.3% of samples were the rice strain and 23.7% were the corn strain. According to Tpi sequences, most samples were the corn strain, and there might be hybrids of rice and corn strains. The phylogenetic tree built based on COⅠ indicated that S. frugiperda in Hainan has the same COⅠ sequence as those in Guangdong (China), Florida (USA), and South Africa. 【Conclusion】 This study clarifies the biotypes and distribution of S. frugiperda in Hainan, providing a reference for early monitoring, warning, and precise control of this pest in Hainan.