The TT8 (TRANSPARENT TESTA 8) gene is an important member of the bHLH (basic helix-loop-helix) family, playing a crucial role in anthocyanin synthesis. In order to explore the effect of TT8 gene on the color of Impatiens uliginosa, the IuTT8 gene was cloned by RT-PCR from Impatiens uliginosa, and its bioinformatics was carried out, qRT-PCR was used to analyze the expression patterns of the gene in different flower colors and different flower development stages. The results showed that: (1) The IuTT8 gene of I. uliginosa was successfully cloned, and its coding region was 2 136 bp, encoding 712 aa, which was a hydrophilic unstable protein. The gDNA was 3 938 bp, with 6 introns. Structural domain analysis showed that the protein belonged to the bHLH superfamily and was homologous to the TT8 proteins of Impatiens glandulifera, Camellia sinensis var. assamica and other species, and they have similar Motifs. (2) IuTT8 clustered with Impatiens glandulifera, and the similarity is about 86.34%; multi-sequence alignment and phylogenetic analysis showed that the domain of TT8 protein was highly conserved. (3) IuTT8 gene was expressed in I. uliginosa with 4 different flower colors and at 4 different stages of flower development. Except for white, the expression level of IuTT8 showed an upward trend followed by a downward trend with the progress of flower development. The expression level of IuTT8 was positively correlated with flower color, with the highest expression level in deep-red flowers and the lowest in the white-flowers. The expression level of IuTT8 in the S3 period of deep-red flower was approximately 48 times higher than that in the S2 period of white flower. The results showed that IuTT8 gene of I. uliginosa is a transcription factor of bHLH family, which was positively correlated with flower color, suggesting that it may play an important role in the regulation of flower color in I. uliginosa.