try darkening the rocks in the background so they have less contrast.  Then try shifting the background tiles up or down 4 pixels or so, that way everything doesnt line up.  Luckily you can shift it really is in pyxel edit.

I like the color use in the foreground, especially the grass. It could use more variation, but it's not bad for a first tilemap!

 Thanks for feed back. This is not for games its only for practice myself and yes I know this is just little more beauty than a crap.Anyway I promise I will train myself. Thank you guys.

Aaaah, my eyes! If this is for a game where the level scrolls... oh, the horror!

 It's way too repetitive. You need to have empty space to let the eyes rest. Also the foreground doesn't stand out enough from the background. On the positive side, it is quite a nice pattern, especially the background one, and nice shading.

I like this grass, and difference between background and foreground colors of tiles, though tiles itselves are hard for my eyes (too contrast, especially background).