In　this　paper,　a　sensitive　graphite/poly(methyl　methacrylate)　(PMMA)　composite　electrode　was　firstly　applied　to　the　determination　of　o-sec-butylphenol　(osBP).　This　polymer　carbon　paste　electrode　(CPE)　effectively　improved　the　soft　surface　of　traditional　CPE,　and　enhanced　the　sensitivity　and　reproducibility.　Factors　influencing　detection　processes　were　optimized　and　kinetic　parameters　were　calculated.　Under　the　optimal　conditions,　the　amperometric　current　density　was　linear　with　the　concentration　of　osBP　in　the　range　from　2.50　x　10(-7)　to　3.55　x　10(-5)　mol　L-1　and　the　detection　limit　was　3.48　x　10(-5)　mol　L-1.　The　proposed　method　was　successfully　used　to　determine　osBP　in　greengrocery　samples　and　satisfactory　results　were　obtained.　(C)　2012　Elsevier　Ltd.　All　rights　reserved.