Abstract Background The RNA-protein interactions play crucial roles in the biological processes. Recent developments to clarify RNA and protein structural features have the urgent need for designing various databases, related to the specificity and the mechanism of the underlying interactions between a protein and an RNA molecule. The majority of these databases have focused on RNAs or proteins macromolecules independently, and they do not have the capability to run integrated queries on the RNA-protein complex. Theses existing databases have a linear query structure. Furthermore, they only focus on interacting (positive) samples and they do not contain non-interacting (negative) samples. Results We developed a Database for RNA-Protein Interaction Network Analysis and Aptamer Design (RPINaptaBASE). RPINaptaBASE has a nested query approach that enables users to apply nonlinear query analysis. The query engine module contains a wide range of features related to RNA and protein sequences and secondary structure elements of these macromolecules, which are helpful to generate custom datasets, especially for machine learning approaches. In this version, more than 175 features were calculated and available to users. It provides a web interface with download management services allowing users to generate desired datasets of unique RNA or protein sequences in independent lists. Furthermore; the web service empowers users to create artificial datasets of positive and negative samples from RNA-protein complexes. In order to present negative samples, the idea of distinguishing protein sequences by their clans and families was employed to efficiently generate non-interacting pairs. Conclusion This database prepares a user-friendly platform to study RNA-protein interactions. It also provides an important simplified contribution to the oligonucleotide-aptamer design process using machine learning algorithms. RPINaptaBASE is freely available at http://rpinbase.com