Thirty-five aphasic patients and ten right brain damaged patients were given two sets of test of semantic-lexical discrimination. One is consisted of five words belonging to the same category (SCT), the other is five words of the different categories (DCT).     Main results are as follows: 1) Statistical control showed that a significant difference existed between aphasic group and right-brain-damaged group on both tests.     2) The difference between correct responses in SCT and in DCT in aphasic group reached the level of statistical significance.     3) Aphasic patients who had gained high score on DCT but low score on SCT examind within three months from the onset showed poor recovery in auditory tasks of SLTA there after, on the other hand, subjects who had gained high score on SCT showed much recovery.     4) SCT showed high correlation with the subdivision of auditory command in SLTA, where as DCT highly correlated with the subdivision of a short sentence in SLTA.     5) SCT may indicate the prognosis of auditory comprehension for aphasics.     6) SCT wonld be useful as a deep test of SLTA.