In this study, in order to find the suitable tuber promoter, an experiment was conducted in Shahid Beheshti University in 2018. For this purpose, promoter sequences of different tuberous plants were searched at NCBI. Sequences were multiple-aligned and the target primers designed from conserved regions. PCR analysis confirmed the presence of the desired promoter in plants of sweet potato and taro. In order to further confirmation, bioinformatic analysis including identification of cis elements, transcription factors, their function, transcription factors with high and low expression were performed. Finally, the identified promoter was compared with patatin class 1 promoter in terms of cis elements and function. Results of bioinformatic analysis indicated that the promoter has specific and general cis elements. General cis elements that are present in most promoters and are involved in activation and regulation of promoters, cellular processes, developmental processes and tolerance to biological and non-biological stresses. Special cis elements of tuber are active in expression of storage protein and starch. Comparison between studied promoter and specific tuber promoter of patatin confirms activity of the studied promoter in the tuber. A tuber promoter can be used to express various proteins in tuber plants in the future.