The classic silver mirror reaction at room temperature in textbooks usually used glucose to react with silver nitrate and ammonium nitrate with the presence of caustic alkalis. But the aldehydes such as acetaldehyde and propionaldehyde were difficult to react under the same condition. In this paper, Na[subscript 2]CO[subscript 3] was used to mediate there action instead of caustic alkalis. In a newly formed ammoniacal-silver solution, a certain dose of Na[subscript 2]CO[subscript 3] solution and aldehydes (formaldehyde, propionaldehyde, n-butyraldehyde and glucose) were added in, and then a silver mirror formed within 2 min at room temperature without stirring or continuous shaking. This result broadened the knowledge of silver mirror reactions with aldehydes and made the scheme simple and easy, enabling the teaching to be more interesting. A survey result showed that 68.4% of preservice teachers at Anhui Normal University are willing to teach the experiment using this improved method.