This study aimed at investigating the efficiency of using Graphmatica Software in teaching quadratic functions on mathematical thinking and achievement of Grade Ten students. The study sample consisted of 68 male and female students from Al Hidda BE Boys School(5-12) and Aisha bint Othman BE Girls School(5-12). This sample was divided into two groups: an experimental group of 34 students who were taught by using Graphmatica and a controlled group of 34 students who were taught by the traditional method. We made sure that there is an equivalence between the two groups concerning the previous achievement and the mathematical thinking. In order to measure the effect of Graphmatica on the experimental group, the researcher used the achievement test and mathematical thinking test. The achievement test, consisting of 28 items, was reviewed and validated by some specialists. According to the Cronbach-Alpha measuring method, the internal consistency was (0.72( To analyze data, the researcher used the means, standard deviation and T test. This study reached the following findings: - There was a statically significant difference at level (0-< 0.05(between the students' means of scores in the achievement test, favoring the students taught the quadratic functions by using Graphmatica. There was a statically significant difference at level (a < 0.05) between the students' means of scores in the mathematical thinking test, favoring the students taught the quadratic functions by using Graphmatica. In the light of those conclusions, the study recommended using Graphmatica software for teaching functions