According to the humanistic-constructivist theory, formative assessment is oriented on the learning process with dimensions of child's development in affective, psychomotor and cognitive areas. In this framework it becomes an important part of teaching-learning process. Taking into consideration areas of affective, psychomotor and cognitive learning development, formative assessment represents a suitable basis (also) for music-education. Music education is oriented towards the process of child's unique way of feeling, thinking and doing music. Music activities of singing, playing, listening and creating stimulate music development in connections with all segments of personality structure. According to the theory of multiple intelligences music intelligence connects with linguistic, logical-mathematical, spatial, motor, intrapersonal and interpersonal intelligences. Music learning establish processes of developing thinking strategies, intuition, imagination, problem and creative thinking etc. (logical-mathematical and lingustic intelligences), orientation in space, motor skills, co- ordination, movement communication etc. (spatial and motor intelligences), attentiveness, co-operation, interactive learning, self-esteem, self-confidence, aesthetic sensitivity etc. (intrapersonal and interpersonal intelligences). The above-mentioned processes of child's learning development should be equally monitored by flexible methods of formative assessment. Formative assessment in music education should be a part of teaching- learning process with continuous and timely feed-back on the quality of the music process. It is not only confirmation or denial of music achievements in singing, playing, listening and creating activities, but has above all a process quality with a formative, diagnostic, informative, summing-up and evaluative role. It is carried out on the basis of criteria which reflect the qualitative level of achieving the planned music objectives. Since music intelligence connects with others, it is necessary to equally monitor child's development in the affective (interpersonal and intrapersonal intelligence) , psychomotor (body and spatial intelligence) and cognitive (linguistic and logical-mathematical intelligence) areas. The feed-back that children get during the learning process helps them identify what they are doing right or wrong, why it is right or wrong, what learning strategies will help them improve their music achievements, and learn about their weak and strong points. But most of all, formative assessment (should) bring stimulation, positive self- confirmation and confidence in their own capabilities. It has the function of promoting musical learning process and shaping reflection on the learning-process state (self- evaluation). Theory and practice of formative assessment in Slovenian primary school trace the above mentioned basis with many solutions of "good practice" and also some difficulties which stimulate towards new findings. In this way formative assessment is an important part of teaching- learning process with continuous influence on its quality.