The image scanned by embedded biochip scanner was filled with many high density of micro-spot arrays. In order to meet the needs of intelligentizing and automatization, a method was proposed to locate the target spots on the biochip image. Firstly, an erosion method based on morphology was applied to this image, and the outline of the spots was got. With horizontal projection was vertical projection, the two-dimension gray matrix was transformed to two one dimension lists. Combined with Fourier transform method and power spectrum transform method, column distance and row distance were calculated for us to search the center in the lists. In view of the fact that the outline image will show two sub-peaks if it is projected, spot diameter was estimated easily. Finally, depending on gravity method and adaptive step length variation searching method, the target locating and segmentation were realized accurately. The method was carried out by C programming language and tested on Pentium Ⅳ 2.2 GHz.The locating process spent 1.8 seconds to dispose a image with 304 spots(row:16,column:19). Locating accuracy came to a hundred percent.
