Hello guys...How to reduce the forward drift of quad ?? Iam using kk2.0 with firmware 1.2..There is no problem with CG..pls help me..Thank u

Its drifting because while you calibrated your ACC, the board wasn't 100% horizontal, hence the drift.
Watch the video to understand the concept, and also would recommend you to upgrade the firmware to the latest for better auto leveling

Thank you for ur suggestion. But i used spirit level to ensure that quad is horizontal during sensor calibration.

I don't know whether its because of the angle at which you shot the pic or otherwise, the spirit level doesn't look exactly at center.
Point is these sensors have better resolution, hence its hard to have an accurate calibration humanely.
Also make sure the FC is firmly installed on your frame.

Easiest way to cancel the drift is go to auto level pid settings menu on the fc and their is pitch and roll below the pid
Its default at 0 u can change it acc to drift to cancel it in -ve or +ve acc to the direction its drifting in

Today the quad stopped drifting but the other issue was it was yawing.

@Chintal Thank  u sir...I did that..But it is now yawing in one side..How to reduce that??

Same way you can put -ve or +ve to roll correction in auto level pid menu
To adjust drift sideways

check your aileron elevator and rudder channel in receiver test and trim them all to 0, and if your Tx has expo put a little of it on those three sticks.