In-flight experiment of MAIS imaging spectrometer and ground-based measurements using GER MARK-V spectroradio-meter simultaneously with the MAIS overpass were performed during Autumn 1995 at the semiarid area of Inner Monogolia

China. Based on these measurement data and MAIS image data

we designed a method for the radiometric calibration of MAIS sensor and an algorithm for reflectance retrieval from its image using 6S code

and discussed the influences of some factors in the retrieval procedure of surface reflectance. The distinguishing feature of this method is that obtaining simultaneously the surface reflectances of the reference target

atmospheric optical depth and water vapor abundance from the measurement data by only one instrument. The results show that the accuracy of MAIS radiometric calibration is about 8% and the estimated accuracy of the retrieved surface reflectance is about 9.6% in the visible and the near infrared wavelengths （0.4—1.2μm）

i. e.

the nearnadir surface reflectance factor is to within about 0.01—0.05 reflectance unit at the reflectance between 3% and 50%. The analysis indicates that the method presented here is suitable to the quantitative analysis of imaging spectral data in China.