Abstract: MADS-box genes play a wide range of roles in flower induction and development, with some genes having multiple functions at apparently unrelated developmental stages. In this study, the phylogenetic tree, conserved structure, gene characteristics, GO and KEGG enrichment analysis, and temporal and spatial expression of MIKC MADS-box gene family in Capsicum annuum L. were systematically analyzed through bioinformatics. A total of 25 MIKC＿MADS genes were identified in Capsicum annuum L., all of which had the N-terminal SRF-TF and C-terminal K-box conserved domain of MIKC＿MADS, with amino acid numbers ranging from 122 aa to 278 aa, and were amphoteric and hydrophilic proteins. Motif analysis showed that all 25 CaMADS-box genes contained three conserved Motif1, Motif2, and Motif4.Chromosome localization found that 25 genes were unevenly distributed on 12 chromosomes, among which chromosome Chr02 localization genes were the most, with a total of 5 genes. Collinearity analysis showed that there were multiple collinearity blocks of CaMADS-box genes in wild Chiltepin. GO enrichment analysis showed that MIKC＿MADS was mainly involved in the early development process of plant growth, mainly in the development of flower organs and endosperm, and KEGG was enriched to glycine, serine and threonine metabolism（ko00260）, glyoxylate and dicarboxylate metabolism（ko00630）, and carbon metabolism（ko01200）.The cis-acting elements were found to be related to photoresponsive elements, salicylic acid, endosperm and other elements. The expression of CaMADS-box in stem, leaf, bud and flower was up-regulated. Through the systematic analysis of MIKC＿MADMADS-BOX gene family characteristics of Capsicum annuum L., which provided reference for the study of plant growth and development in different stages of Capsicum annuum L. breeding, and provides theoretical support for Capsicum annuum L. field breeding.