The simplest description of a plagiarism is either a ‘copy and paste’ for a text even if the source was cited or a change in
some words by taking the meaning without citing the source, where determining the meaning is the hardest and most
complex task. Plagiarism can be seen as one of the cybercrime, similar to (computer viruses, computer hacking, spamming
and the violation of copyrights), therefore, this subject has been interesting because it has become an important part of
the ethics of scientific research. The increasing incidence of plagiarism in the higher education sector, which is considered
acceptable behavior by some, since plagiarism saves time and effort, and gives better results, became a big problem faced
by educational institutions. The main objective of this research is to find a suitable way to detect semantic plagiarism which
occurs on the meaning and making use of synonyms and replace it instead of the original words. This research aims also
to apply a pre-processing for the words of research by using tokenization and stop word removing processes, then tested
whether the research enter under the specialization of computer science or not, where only such research will subject to
semantic plagiarism detection by using WordNet. This research provides an effective way to detect semantic plagiarism for
the written researches, especially by students who have a large plagiarism in their research.