Many edentulous posterior maxilla are found to be compromised by alveolar resorption and increased pneumatization of the sinus. One of the surgical procedures to overcome this anatomical limitation is sinus floor elevation with bone graft, which is reported as more appropriate and more successful procedure. Commonly, if the residual bone height is over 5mm, sinus floor elevation is operated through transcrestal approach using osteotome technique. But, it is possible for patients to feel discomfort during operation and dizziness after operation while malleting, sinus floor elevation, using osteotome technique. Some instruments and methods has been used to overcome these problems and use more easily. The aim of this study is to compare between the surgical procedure of sinus floor elevation using Hatch reamer technique and that of sinus floor elevation using osteotome technique. From 2004 Feb to 2007 Oct, we investigate patients (osteotome group: 72, Hatch reamer group: 70) who were given implant surgery with sinus floor elevation (osteotome group: 92, Hatch reamer group: 98). We analysed gender, age, residual bone height, amount of sinus floor elevation, used graft material, total success rate, failure rate by residual bone height and implant type and discomfort during operation, etc. The results obtained were as follows. 1. In the amount of sinus elevation was osteotome group was 3.85 +/- 1.02 mm and Hatch reamer group was 3.93 +/- 1.38 mm. There was no statistically significant difference between the two groups (P > 0.05). 2. At the total success rate, osteotome group was 92.4% and Hatch reamer group was 94.9%. There was no statistically significant difference between the two groups (P > 0.05). 3. On the discomfort during the operation by using numerical rating scale, osteotome group was 2.87 +/- 0.83 and Hatch reamer group was 1.12 +/- 0.64. There was statistically significant difference between the two groups (P < 0.05). The Hatch reamer group' clinical results was similar to osteotome group and we thought that Hatch reamer technique can overcome the faults of osteotome technique.