The purpose ofthis research was to create and find out the efficiency ofthe Computer Assisted Instruction (CAl) on the topic TIG Welding Process to the standard 90/90. And the learning achievement was analyzed after using this CAl The subjects used in this research were the second -year engineering students Industrial Technology Department the Faculty of Engineering at Rajamangala University of Technology Phra Nakhon who enrolled in this subject. The experiment started at the students did the pre test on the topic TIG Welding Process before they studied this lesson. Then they studied this lessonbyusingCALAfterthattheydidthepost -testonthistopicagain.Theresult ofbothtests was calculated to find out the efficiency of the CAl and analyzed the students learning achievement. The finding revealed that the efficiency ofthe CAl was efficient reached to the standard 90/90. In addition the students learning achievement was increased at significant level of 0.05 after using the CAl.