The molecular mechanism of fruit suture premature of Jinghong mutant peach was explored in this study. Peach fruits of ‘Jinghong’ mutant (JHM) and its wild type (JHW) were used as experimental materials. The hardness, anthocyanin, and the differential expression genes between the suture pulps and the other pulps were compared and analyzed. The results showed that: (1) the fruits of JHM ripened about two weeks later than its wild type fruits, and the suture of JHM matured earlier than the other parts of fruit, and turned red two weeks in advance. (2) The fruit hardness of JHW and JHM gradually decreased during fruit maturation, and the anthocyanin content gradually increased, and all of them changed significantly at 66 days after blooming, also the hardness of the suture was lower, but the anthocyanin content of the suture was higher than that of the other parts of fruit. (3) At 66 days after blooming, the number of differentially expressed genes reached 1 889 between the suture of JHM (MSP) and the fruit surface of JHM (MP). These genes were significantly enriched in the pathway of metabolic pathways, biosynthesis of secondary metabolites, plant hormone signal transduction, phenylpropanoid biosynthesis, etc. Among them, 24 differential candidate genes were screened, including 5 cell wall degradation related genes, 9 pigment synthesis and regulation related genes, 5 ethylene synthesis and conduction related genes, 3 auxin response genes, and 2 NAC transcription factors. (4) To confirm the accuracy and reproducibility of the transcriptome analysis results, 12 genes were selected for qRTPCR validation. The expression profiles of the 12 genes have been assessed using qRTPCR, which were consistent with the RNAseq results, thus confirming our transcriptome analysis. The study found that ethylene diffused from the seed kernel into pulps through suture, which accelerated the expression of ASC1 and ACO1 genes, therefore more ethylene was synthesized. The synthesis of massive amount of ethylene in pulps around the suture site induced the expression of genes related to cell wall degradation and pigment synthesis such as PG, XTH33, CHS, DFR, etc; which finally led to early ripe, softening and changing red.