Based on the morphologic distinctions of apoptosis from necrosis,by using two physical parameters,i.e.,roundness and radius ratio to present the viability of cells,a lossless method based on the differential interference contrast(DIC) image and identifying software,which is used to the viability of cells,is presented in the paper.By adjusting the area parameters of Jurkat cell,the viability of cells and the ratio of apoptosis to necrosis of are were estimated by the method.The experimental results are corresponding with that estimated by MTT method.