桦木科（Betulaceae）主要分布于北半球，具有非常丰富的化石记录，是研究北半球生物地理演化历史非常重要的代表类群。本文首次对桦木科植物化石数据进行全面的搜集和整理。结果显示：桦木科植物化石记录共有889条，主要来自桤木属（Alnus Mill.）、桦木属（Betula Linn.）、鹅耳枥属（Carpinus Linn.）、榛属（Corylus Linn.）和铁木属（Ostrya Scop.）5个现存属以及拟榛属(Corylites Gardner)和古鹅耳枥属（Palaeocarpinus Crane）等12个灭绝属。桦木科植物化石主要分布于北半球的东亚、欧洲和北美洲的晚白垩世至更新世地层中。桦木科植物化石证据表明东亚中纬度地区是晚白垩世桦木科植物早期多样化的中心；古新世-始新世桦木科植物开始多样化，并在欧洲和北美洲多地扩散；到渐新世桦木科大部分灭绝属不再出现，少数类群继续扩张（如桤木属和桦木属）；由于中新世气候变化与地质事件发生，该时期桦木科植物多样性达到顶峰；上新世-更新世桦木科植物化石数量与多样性急剧减少。桦木科植物的历史地理分布格局可能与北半球的地质变化、第四纪的冰川活动、古气候以及古地理的变迁紧密相连。

Betulaceae is mostly distributed in the Northern Hemisphere with abundant fossil records, and it is an important representative group for investigating the biogeographic evolutionary history in the Northern Hemisphere. The fossil records of Betulaceae were comprehensively collected and sorted for the first time in this study. The results show that there are 889 fossil records of Betulaceae, which are mainly from 5 existing genera (namely Alnus Mill., Betula Linn., Carpinus Linn., Corylus Linn., and Ostrya Scop.) and 12 extinct genera (including Corylites Gardner and Palaeocarpinus Crane, etc). Betulaceae fossils are mainly distributed in the stratum from Late Cretaceous to Pleistocene of East Asia, Europe, and North America in the Northern Hemisphere. The fossil evidence of Betulaceae indicates that the midlatitude region in East Asia is the center of early diversification of Betulaceae in the Late Cretaceous; Betulaceae begins to show diversification in the PaleoceneEocene, and expands in Europe and North America; most of the extinct genera of Betulaceae no longer appear in the Oligocene, while a few groups continue to expand (such as Alnus and Betula); the diversity of Betulaceae reaches the peak in Miocene because of climate change and geological event occurrence during this period; the fossil number and diversity of Betulaceae decrease drastically in the Pliocene-Pleistocene. The historical geographical distribution pattern of Betulaceae may be closely associated with geological changes, glacier movement in Quaternary period, and variations of paleoclimate and paleogeography in the Northern Hemisphere.