Im trying to make the best dragon team but i dont no which pokemon to put in so what dragons should i put in my dragon party?

If you really *must* have a dragon team (and i wouldn't advise it, because any good ice-type will blow your team apart), it should look something like this:

Salamence@Leftovers
Dragon Dance
Earthquake
Return
Brick Break

Physical sweeper, DD up, then you'lll be extremely fast and strong, then sweep away.

Latios@Soul Dew (leftovers if you can't get the Dew)
Calm Mind
Dragon Dance (psychic if leftovers)
Dragon Claw
Earthquake (recover if leftovers)

Nobody cares about EVs here if you have Soul Dew. It'll mean Latios' Sp Attack'll be stupidly high and you can destroy damn near anything. If you can't get soul dew, you need EVs etc so drop the physical attacks for more survivability.

Flygon@Leftovers
Sandstorm
Toxic
Earthquake
Screech

Nasty annoyer. Sandstorm and Toxic to leech your opponent's HP, then Screech to force them to switch, because otherwise their lowered defenses will be hit by a powerful Earthquake.

Latias@Soul Dew (leftovers if not)
Calm Mind
Psychic
Dragon Claw
Recover

Simple special sweeper, nowt more, nowt less.

Altaria@Leftovers
Toxic
Perish Song
Haze
Refresh

Altaria's defenses are the only thing going for it, so it has to be an annoyer of some kind. Toxic, then use perish song to force a switch. Haze to deal with anything that tries to raise it's stats, and Refresh to stop altaria being toxicked or paralyzed itself.

Rayquaza@Leftovers
Flamethrower
Thunderbolt
Ancientpower
Rest/Surf

The 00ber-1337 rayquaza, so incredibly cheap, yet no dragon team is complete without him. Give him a special attacking moveset, any one will do. Nobody'll like you for using him, but he's teh only dragon left without going into pokemon that aren't fully evolved.

Anyway, as i said before, a powerful ice type will destroy this team, so really think about this before you train them.

Yes what Octarine Skye said is good for a dragon team (only if you want to collect Dragons) !!!

But:
1. If you want a dragon team you have to beat Elite Four, and there is no point of getting powerful dragons after that! (only if you want to collect Dragons)

So Try this:
Flygon
Salamance
Gyarados
Milotic
Sceptile
Tropius (It is a kind of dragon)

These pokemon high stats and they are available before you beat the elite fours!!!

well im trying to beat the game with every type so like if it was fire i would only have fire pokemon and im on dragons.

Well I was thinking of...
salamence
flygon
altaria
latios (I only have Ruby)
kingdra
gyarados

I say Gyarados, Kingdra, Rayquaza, Groudon(well he looks like a Dragon), Latios, and Salamance.

Oh, i see, you want dragon-description pokemon, not just dragon-type pokemon.

For Kingdra go

Kingdra@Leftovers
Rain Dance
Surf
Ice Beam
Double Team

very good stuff, speedy after a Rain Dance (swift swim) and capable of evasion.

For gyarados,

Gyarados@Leftovers
Dragon Dance
Earthquake
Return
Rest/filler

as he's better as a physical attacker.

um I wouldnt have a gyrados for to long though but its your choice this is just my opinion(I have a Seadra a Dragon Scale now all that I need is a Link Cable for GBASP)

Salamence
Item: Quick Claw
Moveset:
Dragon Dance (Bred off a Gyarados.)
Fly/Aerial Ace/Earthquake
Return/Double Edge (If you really want to risk it.)
Flamethrower

Dragon Dance will speed Salamence up a and power up its Attack. Fly/Aerial Ace for STAB. Return/Earthquake/Double Edge to really destroy. Flamethrower means you don't really have to worry about pure Ice types.

Flygon
Item: ???
Moveset:
Sandstorm
Dig
Toxic
Dragonbreath

Annoyer. A good one. I haven't tested this one out yet, though. Sandstorm, Dig, and Toxic for Annoyance, and Dragonbreath for paralysis and STAB.

Rayquaza
Item: Chestoberry
Moveset:
Ice Beam
Thunderbolt
Rest
Fly/Aerial Ace

Ice Beam does what Dragon Claw can do and more. Thunderbolt... is a filler. Rest is really annoys the opponent when you use it repeatedly. Fly/Aerial Ace for STAB.

Kingdra
Item: ???
Moveset:
Rain Dance
Surf
Rest
Ice Beam

The only reason you should get a Kingdra is since it's a Dragon/Water type. Ice attacks don't really affect it.

I'll add some more later.

Well now i have a problem,1 of the elite four is ice and dragons are really weak against ice

Would kingdra and gyarados be weak against ice since their water/dragon?

Gyarados is Water/Flying, not dragon at all, so he'd have no problem with the ice-types. Kingdra's resistant as well.