According to the requirement of the statistical and scientific database applications, the operators on the databases are defined in the paper. The operators are based on the semantic data model MICSUM[3] and form the algebra on the set of C-relations, atomic summary tables and compound summary tables which are the basic operation objects in MIC-SUM[3]. The algebra called MS algebra. The MS algebra extends the relational algebra with extended operation semantics, the extended set of operation objects and new algebraic opera-tors that support the statistical analysis queries.MS algebra is a theoretical framework for statistical and scientific database query languages.