The paper titled Attitudinal Epithets in a Children Science Book: a Functional Grammar Analysis analyzes Attitudinal Epithets occurrences in a children’s book that intends to explain some scientific phenomena on ‘bugs’. Since Attitudinal Epithets are used by speakers or writers in making personal or subjective comments over a phenomenon, they do not normally occur in writings with scientific genre. This paper reveals one of the children’s science books used as supplementary resources for Science and English lessons in one of the Private Primary Schools in Bandung city, Indonesia. The analysis is conducted by means of descriptive qualitative methods. The findings provide analytical description over the Attitudinal Epithet’s lexical variants that occur in the data; the intensification of Attitudinal Epithets; the scientific, cultural, or other facts in the text preceding or following the Attitudinal Epithets, or outside the text (contextually) to which the speaker directs his personal comment; and the semantic interpretation (including the polarity – negative or positive) towards the Attitudinal Epithets.