As an effort to detect the mood of a blog, regardless of the length and writing style, we propose a hybrid approach to detecting blog text’s mood, which incorporates commonsense knowledge obtained from the general public(ConceptNet) and the Affective Norms English Words (ANEW) list. Our approach picks up blog text’s unique features and compute simple statistics such as term frequency, n-gram, and point-wise mutual information (PMI) for the SVM classification method. In addition, to catch mood transitions in a given blog text, we developed a paragraph-level segmentation based on a mood flow analysis using a revised version of the GuessMood operation of ConceptNet and an ANEW-based affective sensing module. For evaluation, a mood corpus comprised of real blog texts has been built semi-automatically. Our experiments using the corpus show meaningful results for 4 mood types: happy, sad, angry, and fear.