Both are equally important. The key is to balance your high intake of protein w/ the right amounts of carbs and fats which will keep your total amount of calories consistant. So if you have a daily total of 3,500 calories consumed per day, and you maintain that total over a period of time, you can make changes as you see fit according to how well you are or aren't growing. If you aren't gaining any mass (ex. 1-2 lbs per week), then you can increase another 250-500 calories and continue. That said, if you aren't OCD about keeping track of your total calories per day, then you'll never get any consistant mass IME. I would go sign in and register to get a FREE account with fitday, which REALLY helped me.
You need a lot of calories obviously to build muscle. So first thing I'd suggest is increase your protein intake to twice your bodyweight. One gram of protein equals 4 calories. So if you're 200 lbs taking in 400 grams of protein per day, you got 1600 calories right there. Carbohydrates are also 4 calories per gram, and one gram of fat is 9 calories. Just plan accordingly according to your body type (ie. carb tolerance, ect)