35% - payment history - do you make your payments on time and how long have you been making on time payments.
30% - credit utilization ratio - The balance of your cards vs how much credit is available for use.
15% - length of credit - how long have you had your open credit accounts. This is usually the average of all your open accounts.
10% - type of credit you use - cards, car loan, mortgage.
10% - new credit - have you ever noticed your score decreases after you take on a new line of credit? This is because you are now a higher risk borrower with this new debt you have not shown you can consistently pay.