Translating humorous discourse presents a big challenge for the translators, frequently although the intended meaning is transferred; the humorous effect may be lost due to different cultural terminologies. This research aims to unveil the challenge to translate the cultural specific words that contributed to the funny effect in a Diary of a Wimpy Kid series graphic novel. The first volume of the novel was chosen as the data source. The data were analyzed using Vandaele humor translation theory. The culturally loaded expressions words found include the words from the three foreign cultural words categories including material culture (24%), social culture (55%), and gestures and habits (21%). The challenges in preserving humorous effect dealt with the the choice of words/terminologies that could be understood by most readers, the connotative words that are full of intepretations, and the movements that were expressed in onomatopoeic words. It is suggested that the translator should develop the sense of humor and it is also important to consider the readers’ sense of humor.