England captain Moeen Ali won the toss and elected to bat against Pakistan at the National Stadium in Karachi on Thursday.
England, who are actually touring Pakistan for the first time in 17 years, will be in a strong position after their maiden win on Tuesday.
The visiting team won the first match of the seven-match series in Karachi on Tuesday by a margin of six wickets.
For both the visitors, fast bowler Richard Gleason and Pakistan pacer Mohammad Hasnain were replaced by spinner Liam Dawson.
In Lahore and Karachi, the final matches of the series (23 and 25 September) will be played. 28 September, 30 September and 2 October