Purpose: A cost effective tool for the clinical measurement of trunk reposition sense is clearly needed. This study was to analyze intrarater and interrater Reliability of trunk repositioning error (TRE) test which assesses trunk position sense using a portable digital inclinometer. Methods: Twenty four normal healthy subjects were recruited. TRE was measured using a portable digital inclinometer. A digital inclinometer (Acumar-ACU360; Lafayetter Instrument) with precision to $1^{circ}$ was placed on skin over the spinous process from first to second thoracic vertebra (T1-T2) and secured with double-sided tape. TRE test during sitting forward and lateral flexion movement was assessed. When they reached a point approximately 50% of full trunk flexion range, the examiner instructed the subjects to stop and told them. This was the target position that they should try to reproduce exactly. Each subject performed six trials. Results: ICC (2,1) for intrarater reliability (with-day and between-day) of TRE test in sagittal and frontal plane of movement was 0.75 and 0.78 (excellent reliability). Interrater reliability was 0.66 in sagittal and 0.64, frontal plane (fair to good reliability). However, there were poor correlations between an average of TRE test in sagittal and frontal plane. Conclusion: TRE test using a portable digital inclinometer demonstrated good to excellent reliability. The device may be a cost effective clinical measurement for trunk reposition sense measurement.