Abstract: Objective　The aim of this article is to discuss the difference between digital parallel periapical radiograph and digital panoramic radiography in evaluating the angular resorption of alveolar. Methods　By means of digital parallel periapical radiograph and digital panoramic radiography, 55 teeth points in 47 patients with periodontitis were evaluated bone resorption horizontally and vertically. Then compared with the method of clinical operation by analysis of variance .Results Whether measured horizontally or vertically, the result of digital parallel periapical radiograph is more similar as clinical operation than digital panoramic radiography. The results showed that the data of vertical distance of the angular resorption by means of digital parallel periapical radiographs the most similar to the results of the clinical operation. Conclusions　The digitized parallel periapical radiograph can reflect the true extent of the angular resorption in the alveolar bone more accurately.

Key words: angular resorption, digital parallel periapical radiograph, digital panoramic radiography