The Blues were charged with failing to control their players following the angry scenes near the end of their derby defeat, sparked by referee Martin Atkinson awarding a penalty against Johnson for a challenge on Gabriel Agbonlahor.
The match was decided when James Milner converted the resulting spot-kick with eight minutes remaining, with Johnson later labelling Atkinson 'a disgrace'.
Spot of bother: Johnson was penalised for this challenge on Agbonlahor
Television replays showed the defender had got a touch on the balland Johnson said afterwards: 'The referee was a disgrace. He's ruinedthe match and clearly shouldn't be doing these kind of games - it wastoo big for him.
'I got the ball cleanly, everyone could see that, and the ref can'tmake a decision if he's not sure. The rules say if you're not sure, youdon't give a penalty.'
The FA asked Johnson to explain his remarks, and the Blues todayposted a statement on their website confirming the player has beencharged.
It read: 'The FA have today charged Blues defender Roger Johnsonrelating to media comments made after our fixture against Aston Villaat Villa Park on 25 April 2010.
'Johnson has been charged on two counts, relating to his commentsabout the match referee and for his comments about The FA Respectprogramme.
'Johnson has until 20 May 2010 to respond to the charge.'
Blues defender Stephen Carr was also charged with improper conductfor allegedly making an offensive gesture to Villa fans at the end ofthe match.
West Midlands Police are also expected to question Carr over the incident.
Birmingham defender Carr handed one-match ban after for derby anticsTHE MIDLANDER: When is a penalty not a penalty? When it decides the Villa v Birmingham derby, of course.Birmingham City bad boys Carr and Johnson rapped after derby defeatAston Villa 1 Birmingham 0: Blues fury as penalty lifts O'Neill in derby clashBIRMINGHAM CITY FC