Using Brandt model the mess distribution of the late type spiral galaxy NGC 6946 was derived, and the total mass was reestimated to understand the M/L ratio of this galaxy. Two kinds of the rotation curve with shape parameter n=1 and 3.3 were examined. The following are the main results; (1) The total masses of NGC 6946 are $3.1 imes$$10^{11}$ M(n=1) AND $2.8 imes$$10^{11}$ M(n=3.3) respectively. and the corresponding M/L are about 17 and 16 for both cases. (2) The optical image in the blue light, whose radius is 9.6 kpc, has 8$ imes$$10^{10}$ M and 1.4$ imes$$10^{11}$ M. These give the value of M/L about 5 and 8 respectively. (3) The masses and M/L of the nuclear region within 1.2 kpc are 4.0$ imes$$10^{9}$ M 4.7$ imes$$10^9$ M and 3, 4 for both cases. Those of the disk from 1.2 kpc to 9.6 kpc are 7.6$ imes$1$10^{10}$M, 1.4$ imes$$10^{11}$M, and 5, 8. (4) The masses of the outer halo extended to few hundreds kiloparsecs are 2.3$ imes$$10^{11}$ M and 1.4$ imes$$10^{11}$M. The corresponding M/L are about 62 and 37.