Research to defective product reduction in automotive seat production with statistical quality control case study of automotive seat manufacturing. The objective of research were to study the problems that arise in production process and reduce of defective product by statistical quality control method. Studying the problem was arise in trim cover automotive seat production process. Select check sheet for collect data of production and defect. Select pareto chart use for analysis and determined of significant of problem.  Then select fishbone diagrams to analysis the cause of problems. Make action plan for improvement. Trial and improvement as action plan with concept PDCA cycle. Measurement system analysis and performance about inspection of employee for test the ability to separated the good product and defect. After that select control chart type P to control the rate of defect. Finally evaluation of the result and compare performance before and after the improvements with statistical t-test.
	The results were found the problems that arise in production process was occurred by factor of man machine material method and environment. The researcher found the rate of problem before improvement process are 1.36 percent. After take the statistical quality control method use for improvement production process and control variables. Found the rate of problem down to 0.89 percent and the results of the comparative analysis of the defect from the production process before improvement and after improvement were found the rate of defect is reduce significance at the level .05.
