Abstract: Digital evidence has been recognized as a separate category of evidence under the Chinese law, but its concept as well as the unique authentication rules demand further exploration. The concept ‘digital evidence' refers to any probative data or information stored or transmitted in digital form that can be used to prove a case. Data or information, digital form, and evidence are the three key elements of this concept, which distinguish digital evidence from, in a narrow sense, documentary evidence and physical evidence. As to audio-visual material evidence, there is an overlap in-between. Under the current legal regime, the overlapping part follows the collection, preservation, presentation and authentication rules of digital evidence. The unique nature and characteristics of digital evidence give rise to challenges against the conventional evidential rules especially regarding authentication. On the international level, one can observe two trends regarding authentication rules: one is the constantly lowered threshold for formal examination, whereas the other is the increasingly strengthened substantive examination and regulations on collecting evidence. Examining foreign experience can be beneficial to constructing the Chinese rules of authenticating digital evidence.