Avoiding infeasible solutions is essential for fast reconstruction of a distribution network. A coding method without infeasible solutions is put forward by automatically generating the basic ring matrix

and an improved harmony search algorithm is used for solving the networks reconfiguration mathematical model. In order to make full use of the information in the harmony memory bank

the considering probability and trimming probability of the harmony memory bank are improved by imitating the fuzzy clustering method

so both probabilities can adaptively vary with the variation of particle information of the memory bank. Results of simulation on 33-node and 119-node networks show that the improved harmony algorithm has a faster optimization and a better convergence. The validity of this algorithm is also proved by the results.