Objectives The aim of this study is to evaluate effects of hard board applied to acute low back pain patient by using Visual Analogue Scale(VAS) and Pain Rating Score(PRS). Methods From March. 2005 to October. 2005, 20 cases of acute low back pain were divided into 2 groups in sequence. Control group took a rest on the bed(marble-sponge mattress) and sample group took a rest on the hard board. Visual Analogue Scale(VAS) and Pain Rating Score(PRS) were used to assess the change of pain. VAS and PRS were checked 3 times before the treatment, after 3day treatment and 6day treatment. Results 1. After 3day and 6day treatment, there was statistical significance between control and sample group by VAS. 2. After 3day and 6day treatment, there was statistical significance between control and sample group by PRS. Conclusions On treating acute low back pain, it is more effective taking a rest on the hard board than taking a rest on the bed. Further study is needed about effects of hard board applied to acute low back pain patient.