as topic?? how to use it except keep it in my storage yard, i cant access to world map btw, seem useless~~

Straw has three uses:
1) In conjunction with clay, it can be made into bricks
2) In some missions, it can be used for making meat
3) It is used for the working of a Zoo (only works in missions where culture rating is >70)

Based on what you have said, you are clearly playing Nekhen, you don't need to bother with straw here and there's no point letting the stuff build up in an SY as it has no use in this mission.

cattle ranches brickworks use straw also zoo uses straw and meat I think

There is another use for what in many missions is just a nuisance -- you can use it to much more efficiently stock production facilities. It takes some practice to get it right, but often worth it. Basically, you "Allow 3/4" fill of a yard with straw (or any other mostly static resource) then set "Get Maximum" for the resource you need to distribute -- flax for weavers, barley for brewers, etc.

More info here.
[url]http://caesar3.heavengames.com/cgi-bin/caeforumscgi/display.cgi?action=ct&f=25,2756,0,all[/url]

On missions like this, I just set all my storage yards to not accept straw at all. The little delivery dudes drown in the flood or just stand around outside the land-farms and don't get in the way. As a matter of fact, I set my storage yards like that every game because most of the time, straw is pretty useless! My son, however, makes storage yards for straw only and then just tears them down. Waste of money if you ask me...

That's pure genius, if you lack workers you just destroy a SY . and you don't have delivery dudes massing up eternally