Purpose - This study examines the effect of ownership concentration, product diversification, and capital adequacy ratio on bank liquidity in Regional Development Banks (BPD) in Indonesia. Method - The data was collected from BPDs in Indonesia's publicly accessible financial records. There were two phases of the research. In-depth interviews with banking administrators (Board of Directors - BOD and Board of Commissioners - BOC) from several BPDs in Indonesia were conducted in the study's initial phase to acquire background data on the banking management process. The second step involved quantitative research employing multiple regression approaches for secondary data analysis. Finding - The results showed that ownership concentration and capital adequacy affect the level of bank liquidity, while product diversification does not affect bank liquidity. Practical Implication - The results of this study are expected to provide recommendations for capital management and risk management in BPD. In addition, this study can also offer suggestions for local government policies in developing BPD in Indonesia. This is important in supporting Indonesia's overall economic growth. The results can provide recommendations for regulators and banks in making policies to improve banking liquidity in Indonesia. Originality/value: Few studies still model the improvement of liquidity and capital stability in regional development banks in Indonesia using the factors of ownership concentration, product diversification, and capital adequacy. They are mainly related to ownership concentration. Ownership concentration impacts regional development banks' liquidity differently than private banks.