We fabricated an array of platinum quantum dots that are connected by amorphous carbon by electron beam induced deposition. The temperature dependent resistivity is studied. A crossover of the resistivity from the exp(T₀/T)^1/2 behavior to the activated behavior exp(T^*/T) is observed at the critical temperature about 64 K. This crossover behavior is well described by the variation of Coulomb interaction depending on temperature, that is, the interaction with a soft Coulomb gap between the charged grains changes to the strong Coulomb blockade regime with the inelastic tunneling and small mean energy level spacing in a single grain.