The aims of this report are to classify the incorrect data of patients and the errors of dose and dose distribution observed in QA activities on teleradiotherapy chart, and to analyze their frequency. In our department, radiation physicists check several sheets of patient chart to reduce numeric errors before starting radiation therapy and at least once a week, which include history, port diagram, MU calculation or treatment planning summary and daily treatment sheet. The observed errors are classified as followings. 1) Identity of patient, 2) Omitted or unrecorded history sheet even though not including the item related to dose, 3) Omission of port diagram, or omitted or erroneous data, 4) Erroneous calculation of MU and point dose, and important causes, 5) Loss of summary sheet of treatment planning, and erroneous data of patient in the sheet, 6) Erroneous record of radiation therapy, and errors of daily dose, port setup, MU and accumulated dose in the daily treatment sheet, 7) Errors leading inexact dose or dose distribution, errors not administerd even though its possibility, and simply recorded errors, 8) Omission of sign. Number of errors was counted rather than the number of patients. In radiotherapy chart QA from Jun 17, 1996 to Jul 31, 1999, no error of patient identity had been observed. 431 Errors in 399 patient charts had been observed and there were 405 physical errors, 9 cases of omitted or unrecorded history sheet, and 17 unsigned. There were 23 cases (5.7%) of omitted port diagram, 21 cases (5.2%) of omitted data and 73 cases (18.0 %) of erroneous data in port diagram, 13 cases (3.2 %) treated without MU calculation, 68 cases (16.3 %) of erroneous MU, 8 cases (2.0%) of erroneous point dose, 1 case (0.2 %) of omitted treatment planning summary, 11 cases (2.7%) of erroneous input of patient data, 13 cases (3.2%) of uncorrected record of treatment, 20 cases (4.9%) of discordant daily doses in MU calculation sheet and daily treatment sheet, 33 cases (8.1%) of erroneous setup, 52 cases (12.8%) of MU setting error, 61 cases (15.1%) of erroneous accumulated dose. Cases of error leading inexact dose or dose distribution were 239 (59.0 %), cases of error not administered even though its possibility were 142 (35.1 %), and cases of simply recorded error were 24 (5.9 %). The numeric errors observed in radiotherapy chart ranged over various items. Because errors observed can actually contribute to erroneous dose or dose distribution, or have the possibility to lead such errors, thorough QA activity in physical aspects of radiotherapy charts is required.