Abstract:The plaintext password which leaks from the largest Chinese IT community CSDN and RenRen website are taken as examples to analyze the most commonly used password,distribution of password length,distribution of password type,and the situation of choosing e-mail address,phone number,date or English words as password in China network users.The strength of the password depends on the length and complexity.The desired password should be longer and contains lowercase letters,uppercase letters,symbols and numbers.Some basic principles in choosing a password for ordinary Internet users as well as a set of common methods of highstrength password are recommended.Finally,some suggestions on the network security are given.