The current study aimed at developing some scientific concepts by verifying the effectiveness of the use of the virtual laboratory and the continuity of the program's effect on the development of some scientific concepts and terms for slow-learning in sixth grade science. The study sample, selected from pupils in the 6th grade, was divided into: 40-male-and-female-pupil for testing the psychometric properties of the scientific concepts and terms achievement test prepared by the researcher; and 20-slow-learning-pupil for testing the validity of values, who are subdivided into two groups: an experimental group of 10 pupils and a controlling group consisting of 10 pupils, with calculated equivalence for their IQ variables at (70:85). The study tools were: The Stanford Bennet Intelligence Scale, the Fifth Edition to measure IQ quoted and prepared by (Mohamed Taha, Abd Al-Mawgoud Abd Al-Samea), reviewed and supervised by (Mahmoud Abou El Nil (2011)); a list of scientific concepts and terms involved in the determined methodology for the application of the current program (prepared by the researcher); an achievement test of scientific concepts and terms in 6th grade science (prepared by the researcher); the program of the virtual laboratory (prepared by the researcher). The study results showed that: There are statistically significant differences among the average grade levels of slow-learning pupils of the experimental and controlling groups in the post-measurement of developing some scientific concepts and terms in 6th grade science, for the experimental group; there are statistically significant differences among the average grades of slow-learning pupils in the experimental group of pre- and post-measurement for developing some scientific concepts and terms in 6th grade science, for the post-measurement; there are no statistically significant differences among the average grade levels of slow-learning pupils in the experimental group of post- and trace-measurement for developing some scientific concepts and terms in 6th grade science. Key words: Slow Learning - Scientific concepts - Virtual Lab.