Leaf color mutants are valuable tools for elucidating the mechanisms of chlorophyll biosynthesis and chloroplast development， and they play a significant role in understanding plant growth and development processes. In this study， green-leafed tomato material CR11A and yellow-leafed tomato material CH09-805 were used as parents to construct a genetic population to clarify the genetic rules of leaf color. Leaf chloroplast ultrastructure observation and chlorophyll content determination were performed on plants with different leaf colors. Furthermore， BSA-Seq and molecular marker screening were used for leaf color gene mapping and candidate gene analysis. The results showed that the F₁ plants had green leaves， and the F₂ population exhibited a segregation ratio of 12（green）∶3（yellow）∶1（golden）， indicating that tomato leaf color traits are controlled by two pairs of genes with dominant epistasis. Observation of chloroplast ultrastructure and determination of chlorophyll content revealed that the chloroplast ultrastructure of golden yellow leaves was severely damaged， and their chlorophyll content was significantly lower than that of pale yellow and green leaves. Using BSA-Seq and molecular marker screening， the tomato leaf color gene Sllc1 was mapped to a 114.53 kb physical distance on chromosome 7. The candidate interval included 13 annotated genes. Based on gene annotation information and expression identification， Solyc07g053630 and Solyc07g053640 were identified as candidate genes for Sllc1. This study identified candidate genes for tomato leaf color， providing important material and gene resources for elucidating the molecular mechanisms of tomato leaf color formation.