Aroma is one of the most important sensory characteristics of fruit quality. Here, the aroma composition of mature fruits of 202 pear cultivars was detected by headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). As a result, 221 major volatile components were detected, among which aldehydes, esters and alcohols were the most dominant aroma components. We also found Pyrus communis L. had the highest volatile content, followed by Pyrus sinkiangensis Yu, Pyrus ussuriensis Maxim., Pyrus bretschneideri Rehd., Hybrid Breeding cultivar group, Chinese sand pears (Pyrus pyrifolia Nakai), and Japanese and Korean (J&K) sand pears (Pyrus pyrifolia Nakai). In addition, the aroma composition and contents varied greatly among the different ripening-period groups. Finally, the fruits of pear germplasms also showed geographical flavor characteristics. These basic data and results could help us better understanding the variations of aroma quality among pear varieties and promote the development of pear breeding program.