Compare with Bermuda grass, Cynodon dactylon.
hortster

Thank you, Hortster. It is right. That is Bermuda grass.
I will find some herbicides to kill it.

The main force in Bermuda eradication is TENACITY. Also, timing. It is best to treat and re-treat it a couple of weeks apart in late summer when it is beginning to store carbohydrates in its roots for the next season, thereby taking as much herbicide down to the roots as possible. Right now you can topkill it but it is drawing carbohydrates UP for new topgrowth. Your applications will be much less effective now since unaffected deep roots will eventually return. Toward fall use the recommended rate or slightly less so as not to kill the topgrowth before the product can be thoruoughly absorbed and translocated. Remember to apply the product a couple of feet beyond where you can see the Bermuda as the runners sneak past viewing under the "good" turf. Since you seldom get more than 90% of it in a season, suggest another round next year. This is what is meant by "tenacious." Good luck!
hortster