Abstract: A new process for selective catalytic oxidation of β-carotene was proposed.Optimum oxidation conditions were determined by uniform test design and simplex optimization.β-Carotene was synthesized from 3-methyl-5-(2,6,6-trimethyl-1-cycolhex-en-1-yl)-1,3-pentadienylphosphonates and 2,7-dimethyl-2,4,6-octatriene-1,8-dial with a yield of 68%.Proper catalytic oxidation conditions were: β-carotene 6.8 g, compounded catalyst 0.45 g, dichloromethane 250 ml, saturated sodium hypochlorite 50 ml and reaction temperature -5℃.Carbon dioxide was used to maintain a weak acidic system.The process was completed in 40 min.Purification of β-carotene and canthaxanthin was made by recrystallization.