The purposes of the research were to construct and to evaluate the efficiency of computer- assisted instruction program for reading vernier caliper and micrometer based on criteria and analyze the learning achievement of the student after using computer - assisted instruction. The samples were the first year undergraduate 17 subjects students at Rajamangala University of Technology Phra Nakhon in 2006 participated in this study. The experiment was conducted by using pretest post test design. The efficiency of the computer - assisted instruction was calculated and was the learning achievement of students after studying analyzed. The result revealed that the efficiency of the computer - assisted instruction was efficient in criteria and learning achievement significantly increased at .05 level.