the instruction to the smart card or else if it is the device receives the password input by the user encloses it to the password checking instruction sends the instruction enclosed with the password to the smart card receives the result of executing the password checking instruction from the smart card and sends the result to the upper computer the solution of the invention is used for improving the security of inputting a password in avoidance that the password is intercepted when being transmitted application_number US 81204210 A description a clear and complete description of the solutions in the embodiments of the invention will be given below with the drawings of the embodiments obviously the embodiments described here are only parts of embodiments of the invention and any others accomplished by those skilled in the art without any inventive work based on the above mentioned embodiments will be still in the scope of protection of the invention a method for inputting a password is given in the embodiment 1 of the invention as shown in fig1 said method includes step 101 a password inputting device receives an instruction from a card reader the instruction received confirms to the 7816 regulation in format a world wide acknowledged smart card regulation the instruction includes fields of cla ins p1 p2 lc and data the cla field abbreviation of class refers to the type of the instruction one byte in length the ins field abbreviation of instruction one byte in length refers to a designated instruction an instruction name.