Abstract: F2 population was constructed using tomato material 19912 containing the resistance gene Frl to tomato neck rot root rot and susceptible material Moneymaker.The association analysis method of BSA was used to further analyze the candidate intervals of the resistance gene Frl in tomato fusarium crown and root rot, with the aim of screening candidate intervals for resistance genes.The results showed that by resequencing the father and mother parents and analyzing the mixed pool association of BSA,the Frl gene was located in the 2.63-81.19 Mb interval of chromosome 1.By using SNP typing technology and combining with the sequencing results of BSA,the interval was reduced to 17.4-23.5 Mb.This study will not only provide a basis for the cloning and application of disease resistance genes, but also lay a foundation for analyzing the resistance mechanism of tomato neck rot root rot disease.