This paper presents numerical stress calculation in the stationary temperature domain for a hybride structure with fiber composite (for example, based on the epoxy risen as matrice of prepreg) and metalic part (other part of structure or metalic mould), as different material according to their own thermical behaviour. The thermal stress analysis is based on the finite element method. A sample problem involving such a composite plate and metalic part of structure or mould at two different temperature levels, corresponding to curing process (co-curing) and operating temperatures respectively, is calculated and discussed. The specifics of composite are emphasized particularly for thermal coefficients (especially shear coefficient is different than zero, there are situations when some of coefficients could be less then zero). This composites as generalized orthotropic material are completelly different than isotropic material (for isotropic material shear coefficient is always equal zero). It was pointed out also that the calculation for the initial crack to appear in the lamellae (the most common occurrence of cracks in the matrix) can be set with a reserve of elasticity or without reserve.