The present invention relates to method for assessment of functional damage in spinal cord injury (SCI). At present there is no method that can measure functional damage to autonomic nervous systems in spina/ cord injured persons. There has been tremendous increase in number of spinal cord injured (SCI) patients around the world due to variety of reasons. Considering this, a method has been invented to bring out a relation between functional damage to autonomic nervous system and R-R variability. The method uses R-R intervals derived from ECG or any universally available procedure. The R-R interval responses are recorded in two different modes or positions: sitting and five seconds deep respiration. In each mode, at a time 150 seconds R-R interval data is acquired. The R-R time series spectra! pattern has three distinct frequency regions； a very low frequency (VLF) band, a low frequency (LF) band and a high frequency (HF) band. Two independent indices StB and DbB are calculated from spectral plots. Damage to autonomic nervous system due to spinal cord injury is calculated using functional efficiency factor ROR. Component values are in percentage between 0 and 100
