Abstract: Vocabulary discovery strategy (VDS) is one of the important components in English vocabulary learning strategy. This present study aims to make a comparative study of vocabulary discovery strategy used by Chinese and Thai non-English major students. 399 non-English major students participated in the study. The data collection was carried out through a questionnaire and a vocabulary level test. The results reveal that the frequency of the overall vocabulary discovery strategy use is moderate; With regard to the subcategory of VDS, Chinese students employed more frequent strategies for guessing and socializing than Thai students, while Thai students utilized more strategies for dictionary than Chinese students; No gender and major orientation differences on the VDS use has been significantly found between Chinese and Thai non-English major students; Guessing and dictionary strategies of VDS could predict the vocabulary level test.