hi, im 20 years old, and my body physique is pretty much medium sized, although i have a fat stomach....i think it was because of my improper diet before...im 5"6, 168lbs.
anyways, for the last 3 weeks, i have been training with the following program, hoping to gain muscle mass and lose weight at the same time.

1) Cardio - swimming for approx. 1 hour
2) Workout: Chest/Triceps/ (crunches x 50 reps x 2 sets)
3) Cardio - swimming for approx. 1 hour
4) Workout: Back/Biceps/Shoulders/ (crunches x 50 reps x 2 sets)
5) Cardio - swimming for approx. 1 hour
6) Workout: Legs/ abs focused day
7) rest

how does it look to you guys? im also maintaining a good diet, eating most things that contain low calories, etc..

any possible improvements?
my goal would be losing most of the body fat and build minor muscle mass(focus more on toning) by next summer....(of course i will maintain exercising after^^)

I'd switch shoulders to chest day along with your triceps. Alot of the shoulder is hit when you perform chest movements and you can utilize that to pre-exhaust the delts.

I think you're not working out enough. What I mean is, you hit each muscle group once a week. You'd get better results hitting each muscle 2 or 3 times a week, with the appropriate volume.

either 3 fullbody trainings a week, or some sort of upper/lower or push/pull split would accomplish this.

a muscle will start to de-train after 48 hours of not being worked, at least in novice lifters.
long time body builders, their body's don't detrain as fast, and they need a huge amount of volume, with less frequency.

If you choose to stick your routine, then follow LV's advice about shoulders.

I would first edit your goal. "You can't chase two rabbits at the same time". You should either bulk up and maintain bodyfat where it is OR cut down and maintain muscle mass where it is. This way you will get optimal results.

If you want to stay with this regiment.....that's just fine for now. However, I kinda' agree with LV you should change something out. Not so much shoulders. Shoulders are used no matter if you are pulling weight (back) or pushing it (chest). YOU should change out leg day and put it in between the two upper body days.....and put some emphasis into those legs.

Swimming is great, but it is too easy to get very good at it. If your swimming for an hour you probably have it down pack (so you won't be burning calories efficiently if at all). I recommend interval swimming (i.e. freestyle to backstroke or swan) OR do 5 minutes of jumping jacks or jump rope than hit the pool for 15 min or so.....if you can.

goodluck

Good posts guys. Def. choose one goal and stick with it. Conflicting goals is the first place you are messing up. To lose fat you must be in a caloric deficit generally, and to gain muscle you must be in a caloric surplus.

Secondly, I would follow Malkore's advice with a 3 day full body training split.

thanks for the advice guys...
im not looking to build myself to look "very buff", i just want a more "lean" and tighten muscled body...
im not sure if that make senses or not...
in anyway, im trying desperately to lose the stomach fat, but i would also like to "add little" mass while "tightening" the muscles at the same time...
im not sure if its feasible...

One goal at a time my friend. Don't contradict yourself. If you have some unwanted body fat to lose, focus on that first. You still need to lift weights so you maintain your current lean body mass, but you also need to couple this with a balanced caloric deficit eating regiment as well as a cardio routine.

Once you reach your desired levels of body fat, then you can start adding LBM by bumping your caloric intake to a surplus.