The robust detection of spot object in image with complicated backgrou nd and interference is a challenging problem.The circular spots appear as round local peaks or valleys in image space,and they reflect the omnidirectional symmetry and Gaussian distribution characteristics.A ccording to these observations,a novel rotating line scanning operator is proposed to achieve prof ile feature analysis of the spot object.By combining local peak analysis and gradient information,the spot d et ection and segmentation can be achieved.Experimental tests show that the proposed algorithm is adaptive to spots′ appearance variation (size,local contrast and intensity).For mobile phone partition resid ual sand detection,the accuracy of the proposed method achieves 0.993,and for microaneurysms detection in retinal image,the accuracy is 0.42under the clinically acceptable false positive rate (1.08FP/im a ge).The method presents promising performance and excellent robustness in variou s real images.