OBJECTIVE: To explore the visible near-infrared spectroscopic (VNIRS) characteristics of intracerebral hematoma, and provide experimental basis for hematoma localization and residual detection in hypertensive intracerebral hemorrhage (HICH) surgery.METHODS: Using VNIRS, spectral data of cerebral hematoma and cortex were collected during HICH craniotomy, and characteristic spectra were matched with paired-sample T-test. A partial least squares (PLS) quantitative model for cerebral hematoma spectra was established.RESULTS: The reflectance of cerebral hematoma spectra in the 500-800 nm band was lower than that of the cortex, and there were statistically significant differences in the 510, 565, and 630 nm bands (P < 0.05). The calibration correlation coefficient of the PLS quantitative model for cerebral hematoma spectra was R-2 = 0.988, the cross-validation correlation coefficient was R(2)cv = 0.982, the root mean square error of calibration was RMSEC = 0.101, the root mean square error of cross-validation was RMSEV = 0.122, the external validation correlation coefficient was CORRELATION = 0.902, and the root mean square error of prediction was RMSEP = 0.426, indicating that the model had high fitting degree and good predictive ability.CONCLUSIONS: VNIRS as a noninvasive, real-time and portable analysis technology, can be used for real-time detection of hematoma during HICH surgery, and provide reliable basis for hematoma localization and residual detection.