A new single image super-resolution reconstruction algorithm is presented based on projection. Using the Kronecker product of two matrices, the vector based observation model is converted to an equivalent matrix based model. Further more, a projective operator is defined according to the new observation model. Superresolution reconstruction result can be obtained by this operator directly. Meanwhile, this operator can be used to improve the reconstruction impression acquired by other super-resolution algorithms. Theoretic results and the simulations show that the algorithm is valid. For the standard Lenna image,the PSNR value increased about 2.5 dB compared with those of both the Linear and B-Spline interpolation method.