The use of computer programs in learning mathematics can help students construct mathematical concepts. Therefore, computer media is needed in learning mathematics today. One computer program that is often used by teachers to help explain geometry concepts is Geogebra. This community service activity aims to provide training on the use of Geogebra in instilling straight-line concepts, and graphs of quadratic functions, for junior and senior high school teachers in Jember Regency, which is attended by 30 people. This training was conducted in March 2016 for 2 training sessions, held at Jember 3 Public Middle School. The method used: presentation, practice, discussion, demonstration. Furthermore, assistance is provided at the school where the training participants teach. As a result, there was an increase in skills in utilizing the Geogebra program to teach students about the concept of straight lines, and graphs of quadratic functions. The expected output of the community service activities are: (1) abdimas articles which are published in journals / electronic media (2) Handbook on how to operate the Geogebra program.