: There are several reasons to specify UML models in a formal way The most important are to avoid inconsistencies and ambiguities and to do verification and forecasting of system properties. In this paper we propose a systematic approach to transform UML static models into algebraic specifications. We define the GSBLoo algebraic language to cope with concepts of UML. Firstly, we give a formal description for UML static models using GSBLoo . Then, we describe how to translate UML constructs to GSBLoo constructs. In particular, we show how to transform UML relations into GSBLoo . We propose a system of transformation rules to translate OCL constraints to GSBLoo .