I am creating Cash flow statement.
But I don't understand treasury stock section and its impact on cash flow statement.

In Balance SHEET it says

Common Stock held in Treasury at cost
2011 (6146) and 2012 (6004)

Common Stock issue from treasury for stock options 802
Repurchase of Common Stock 1384

Treasury Stock
Opening Book Value 6146
Repurchase 1384
Issue Proceeds (802)
Compensation EXP (724)
Ending BOOK VALUE ( 6004)

Now what do I have to show in CASH FLOW STATEMENT Financing Activities SECTION.

They are financing activities as you have identifed and you have identified the inflows and outflows so basically your problem is how to caption these transactions

Share based compensation is not a cash flow so you are left with stock repurchased and stock issued