Abstract: High sugar（8%）and common sugar（4.5%）tomatoes were used as the research materials. Fruit samples were collected at the mature green stage，the breaker stage，the pink stage，and the red ripe stage. Transcriptome sequencing was conducted to analyze the differences in gene expression between these two materials. The analysis revealed there 288 differentially expressed genes（DEGs）between common and high sugar tomatoes across these four stages，with 174 down-regulated DEGs and 114 up-regulated DEGs. Notably，the breaker stage showed the highest number of DEGs between these two materials. GO analysis demonstrated significant enrichment of DEGs and GO terms at the breaker stage with the greatest number of GO terms identified at this stage. Furthermore，KEGG analysis showed that the DEGs and related pathways，particularly sugar and acid metabolism pathways，were concentrated at the breaker stage. Clustering analysis of key enzyme genes involved in sugar and acid metabolism identified 30 DEGs.

Key words: tomato, sugar content, maturity stage, transcriptome analysis