How to respond to this gambit?

Many people seem to play this gambit against me: 

What is the best way to ®espond?

Read the book of Moskalenko. He says 4...c4 is a good option

Yes, I agree with @germagno - 4...c4 should work well.  I haven't read the book, but it seems logical - now the d-pawn cannot get to d4 without being sniped by the c-pawn.  White can try playing d3 to force the matter, but white's b-pawn is still vulnerable - after 5.a3 (5.c3 locks down the d-pawn, and leaving the b-pawn is no good since ...Bxb4 will help black develop) 5...a5 (to undermine the pawn - 5...Nc6 gets hit by 6.b5) 6.b5 (6.bxa5 Qxa5 will leave white with issues developing and a weak a-pawn) 6...a4! and the b-pawn should eventually be won at such time as black is ready to scoop it up.

FYI, ChessTempo.com's database shows the ideas 4...b6 and 4...cxb4 as both scoring very well for black.  I would say 4...b6 is the more practical move, both because it continues the fight for d4 and because white probably has plenty of preparation for 4...cxb4.

Thanks

For the lazy among us, if it fits into your repertoire versus the Advance Variation (or if you think that White is not familiar with that line as well), you can avoid the gambit with 3...Bd7. Neil McDonald recommended this in How to Play Against 1 e4.

I came here to say exactly this. +1

...cxb4 5)a3 Nc6 6)axb4 Bxb4 7)c3 Be7 8)d4 Bd7 9)Bd3 b5! with idea ...Qb6.But after Qb6 i no know how continue,what should u play?

c5-c4 is my preferred response to the Wing Gambit. It avoids the accepted gambit (which is what most white players are hoping for) while giving black a flexible, natural game.

Here's one I just played against a 2000-rated opponent who used the Wing Gambit against me.

Go French! :D

Pawn Wedge line is cool too (d4 instead of c4)