There are disclosed a network interference evaluating method, a dynamic channel assignment method and apparatus used in wireless networks. The dynamic channel assignment method used in a wireless network, comprising steps of: calculating each pair of visual delayed time for each pair of basic service sets based on received signal strength indicators, traffic information and rate information, and evaluating an overall network interference under a current channel allocation based on the calculated visual delayed time; constructing an undirected graph so that each basic service set is located at a vertex, and each connection line between each pair of basic service sets has a weight obtained from the pair of visual delayed time for this pair of basic service sets; coloring the undirected graph to get a new channel allocation approach and an optimized minimal overall network interference under this new channel allocation approach; comparing a difference between the evaluated overall network interference under the current channel allocation and the optimized minimal overall network interference with a predetermined threshold; and changing channel allocation for the basic service sets according to the new channel allocation approach if the difference is larger than the predetermined threshold.