Abstract: An improved dust collecting system for a coke oven employs a bag filter dust collector as a common dust collector for both the coke discharge operation and the coal charging operation. First, the dust spouted out in the coke discharge operation and then successively and alternatingly, the dust spouted out in the coal charging operation and in the coke discharge operation are collected, whereby fine coal particles deposited out in the coal charging step are deposited on the layer of the fine coke particles firstly deposited out in the coke discharging operation. In addition, a combustion chamber is provided for burning the gases and dusts spouted off in the coal charging operation and a pre-dust wet-type collector is utilized therein for preliminary filtering before the same is fed to the common bag filter dust collector.