Due to the requirements of the Web 2.0 applications and the relational databaseshave a limitation in horizontal scalability. NoSQL databases have become moreand more popular in recent years. However, it is not easy to select a databasethat is suitable for a specific use. This thesis describes the detailed design, im plementation and final performance evaluation of a key-value NoSQL databasefor the SensibleThings platform, which is an Internet of Things platform. Thethesis starts by comparing the different types of NoSQL databases to select themost appropriate one. During the implementation of the database, the algorithms for data partition, data access, replication, addition and removal ofnodes, failure detection and handling are dealt with. The final results for theload distribution and the performance evaluation are also presented in this pa per. At the end of the thesis, some problems and improvements that need betaken into consideration in the futures.