Giving up the homogeneity of the cosmological principle that holds for decades , I consider a spherically symmetric but inhomogeneous Lemaitre -Tolman-Bondi (LTB) metric , which provides an simple toy model for an inhomogeneous universe. To examine an already known mathematical example, I derive the appropriate equations which determine the definition of the redshift. Without dark energy , the accelerating expansion observed by distant supernova data can also be described by spatial variation in matter density.