A variety of methods to evaluate hindlimb locomotor function following a spinal cord injury (SCI) have been proposed and modified over time. Especially the Basso Mouse Scale score (BMS) has been widely used because it is easily accessible without instruments. However, some points of the BMS still should be improved because the BMS mainly focuses on hindlimb movement rather than on graded changes in body support ability, and the definition of single score is made by combing multiple criteria in the BMS. Previously we established the Body Support Scale score (BSS) that was specially focused on the body support ability. In this study, we aimed to establish a new scoring method Toyama Mouse Score (TMS) by rearranging and simplifying the BMS and combining it with the BSS. The TMS was summative scoring of 9 items that contain a frequency of heel movement, movement of knees, thighs and toes, which are not checked in the BMS measurement. SCI mice were observed in an open field and scored using the TMS, BMS and BSS for 11 days after contusive injury. To compare the precision the TMS and BMS, we calculated the coefficients of variations (CV) of the data in the 11-day observation periods. The averaged CV of the TMS data was significantly lower than that of the BMS. By single observer, the TMS could distinguish slight differences in hindlimb functions, which were not detected in the BMS. In an independent experiment, score points observed by different observers for one hindlimb at 3 days post injury were picked up to compare variations in intra evaluators between the TMS and BMS. The results showed low CV value of the TMS compared with that of the BMS. These results suggest that the TMS is more reliable scoring with little deviation in intra samples and in intra observers compared to the BMS. The TMS may be a useful new reliable method that is easy to access and offers a clear-cut summative point system, resulting in better evaluation with high sensitivity and low variation.