This research synthesis investigated the effectiveness of synthetic phonic for improving the English reading skills of students with below average English reading skills. The research synthesis was focused on which variations in Jolly phonics program training are associated with differences in outcomes of reading level of students. Computer-assisted research was done. Educational Resources Information center (ERIC) database, JSTOR, Science direct and Google Scholar were the primary information databases which were searched for articles in English published 2003 – 2023 to find out relevant content. An online search through Google search engine was also conducted. The consequences of JP training were examined in 21 studies, which include 7518 participants who had been assessed and diagnosed as having below average English reading skills. The consequences of the intervention were reported in all research. Improvement in the reading skill is the most common outcome of the intervention program that is reported in the studies. Results claims that JP program is an effective intervention for improving English reading skills. As a whole the findings of the studies included in the synthesis provide evidence for the effectiveness of the intervention program that is jolly phonics. Especially for the enhancement of the English reading in the struggling student’s jolly phonics is effective strategy. Therefore, this program is recommended as an evidence-based intervention for this purpose.