PROBLEM TO BE SOLVED: To provide a radiation imaging system which can restrict coming-off of a connector from an electronic cassette and a range where the electronic cassette can be carried during storage.SOLUTION: A radiation imaging system 10 comprises: a portable radiation imaging device 12 provided with a connection part 24 to which a wired connection member 14 connected with an external power cable 43 is connected and detecting a radiation generated by a radiation generator a connection member 14 which is connected to the connection part 24 lock means which is provided in the radiation imaging device 12 and restricts removal of the connection member 15 connected to the connection part 24 imaging control means which is provided separately from the radiation imaging device 12, makes the radiation generator generate the radiation and exchanges information with the radiation imaging device 12 and lock release means which is provided in the radiation imaging device 12 and releases the lock state by the lock means with a signal output from the imaging control means.
