A method and a system for preserving sensor data based on a time key, and a recording medium thereof are provided. The time key based sensor data security preserving method includes encrypting the sensor data with an encryption key obtained using a time key based polynomial derived using random numbers and a secret key which is shared by a sensor node and an application system; and decrypting the encrypted sensor data with a decryption key obtained by deriving the same polynomial as the time key based polynomial using the random numbers and the secret key. Thus, integrity and confidentiality of the sensor data can be preserved.