Background：Despite the challenge of associating childhood risk factors with adult asthma, a systematic synthesis of evidence on the risk factors is lacking. We performed a systematic review and meta-analysis of the association between childhood risk factors and adult asthma. Methods：We systematically searched the PubMed and Web of Science electronic databases from the inception to our last search date (10 November 2022). The search strategy included key words for risk childhood risk factors and adult asthma. The Newcastle-Ottawa scale (NOS) was used to assess the quality of the included studies. Results: Of 25 eligible articles, 18 domains of childhood risk factors were assessed. Bronchiolitis/wheezing (pooled adjusted OR=5.32; 95% CI: 2.83-10.02; I 2=58%; number of outcomes [N] =7), eczema (pooled adjusted OR=2.01; 95% CI: 1.42-2.84; I 2=79%; N=8), hay fever (pooled adjusted OR=3.31; 95% CI: 2.26-4.85; I 2=0%; N=2), positive reaction of skin prick test (SPT)(pooled adjusted OR=2.37; 95% CI: 1.18-4.77; I 2=54%; N=3), airway hyperresponsiveness (AHR)(pooled adjusted OR=2.73; 95% CI: 1.52-4.88; I 2=0%; N=2) and pool lung function (pooled adjusted OR=2.88; 95% CI: 1.41-5.87; I 2=0%; N=2) during childhood increased the risk of adult asthma. Association of childhood asthma and rhinitis with adult asthma needs more studies to confirm. Childhood body mass index (BMI) wasn’t found to be related to adult asthma (pooled adjusted OR=1.06; 95% CI: 0.57-1.97; I 2=78%; N=3). The evidence was insufficient to draw conclusion for passive smoking, household economical condition, keeping pets, girls matured early, slept for insufficient durations, being abused, pneumonia, adenoidectomy and/or tonsillectomy, cognitive ability. Conclusion: Childhood bronchiolitis/wheezing, eczema, hay fever, positive reaction of SPT, AHR and poor lung function were associated with an increased risk of adult asthma. These identified risk factors would be helpful for the early prevention of the adult asthma. And future studies might need to clarify and supplement existing conclusions from more aspects.