This research aims to determine touristic destination’s theme (especially tourism activity theme) from the tourism web documents for geographic information system (GIS) applications, i.e. guiding the main interesting tourism activities to tourists. There are two major problems of the theme acquisition; tourism activity extraction and tourism activity generalization. Therefore, this research proposes of using Naïve Bayes Classifier to determine word co-occurrences between verbs and nouns with the tourism activity concept from web documents. Furthermore, this research also applies the fuzzy concept along with the imputation technique, to determine the tourism activity theme by generalizing the extracted tourism activity. The result of the tourism activity extraction shows successfully the precision and recall of 85% and 77%, respectively, with Mean Reciprocal Rank (MRR) of the tourism activity theme is 0.5.