Hi, my penis has downward curve but i want it to be straight or upward curved , i don't wanna any surgery i wanna fix it by doing some excercise .?

No luck: It is unlikely that either surgery or exercise will change to curvature at this point. Most likely, the curve is due to a small amount of scar tissue developed when the penis becomes aroused. As long as the curve is not interfering with the function of intercourse, i would recommend leaving it alone.

You can stretch it: This sounds like peyronie's disease. Stretching may only help if used in conjunction with injectable medication. There are two different opinions on if this modality works, but if injections fail, surgery will give the best result.