I think it's a really good start. Add some more shading and it'll be great, hmm... advice:
Shading - add some more shading to show the bone structures, this'll make it look more three dimensional and less two dimensional.
eye - It might just be me, but the eye looks really small and stretched, isn't it meant to be a bit more spaced out, and less stretched? That could be to do with my lack of knowledge on dragons though You need to give it a light spot, and dark spot. xD
Basically, everything looks great for a sketch. Now you need to make it into a masterpiece Make sure you add more shading to fix the bone structure, once done properly your picture will be great. Well done and good luck
To bring your drawing to the next level, add shading. Like Kirsten said, this will make your drawing look less "two-dimensional" and more "three-dimensional."
I think the drawing would look even better if you added some texture. Maybe give the dragon scales.
Hope this helped,
~~~Sakura~~~
Odi et amo. quare id faciam, fortasse requiris? nescio, sed fieri sentio et excrucior. -Catullus, Carmen 85
You need to give it a light spot, and dark spot. xD
Make sure you add more shading to fix the bone structure, once done properly your picture will be great. Well done and good luck 
