Technology is very important for human activities, especially in teaching and learning. Every people knew that technology based-learning is very useful in this era. The objectives of study were to explain the effectiveness of Rosetta stone software usage on students’ pronunciation development at the Eighth Grade of SMP IT PAPB Semarang and to find out its pedagogical implications. This research is quantitative research. The researcher used Quasi-Experimental design to measure the effectiveness of Rosetta Stone software on student’s pronunciation development. For this research, the researcher invited the students of class 8C as the control class and class 8E as the experimental class. The researcher used a pre-test, a post-test, and questionnaires as the data collection technique. After collecting the data, the researcher analyzed the result by normality, homogeinity, and hypothesis test. The study showed that: The test of hypothesis using t-test formula shows the value of the t-test is higher than the value of the t-table. The value of t-test is 2.300, and the value of t-table on α = 5% is 2.002 (2.300 < 2.002). Then the hypothesis is accepted and Ho was rejected. The results of this research showed that most of students like English because English is fun lesson, although it is difficult for them. After using Rosetta Stone software, students felt easier and happier to understand and to practice pronunciation. Teacher realized that Rosetta Stone can help students’ learning and the teacher will use this software for future teaching and learning. Therefore, using Rosetta Stone software as learning media is effective.