Natural rubber samples were melted with H2SO4 and HF by microwave counteract system, and then the manganese content in rubber was measured by UV spectrophotometry.Using this method, the sample preparation efficiency was improved 15~20 times as fast as by GB/T 8296-2008.The test result showed: ① the best digestion condition was 3.5 mL H2S04 and 0.5 mL HF as the digestion reagent with the temperature raised to 180 ℃ within 2 min and maintained for 10 min; ② the changing of digestion temperature had a significant effect to test result, the digestion time had a definite effect and the digestion reagent had an inconspicuous effect.