Abstract: Result certainty is very important for SEC reserve estimation. A useful method to check the reasonableness of SEC petroleum proven reserve estimation was proposed, based on the uncertainty degree of reserve estimation, through establishing the relationship between estimated decline rate and natural or composite decline rate. The method utilized the comparison of real production data and decline rate with reserve estimation from multi-angles. The evaluation method is effective in practical examination, and is useful for reserve appraisers to improve reserve estimation results.