A method and an apparatus for storing data are provided. The method includes: acquiring target data, the target data including first key-value pair data, object data or array data, the key-value pair data including key data and value data, the object data including second key-value pair data, and the array data including object data; determining an object data number of the object data included in the target data, an array data number of the array data included in the target data, a first key-value pair data number of the first key-value pair data included in the target data, and a second key-value pair data number of the second key-value pair data included in the target data; determining a storage space based on the determined numbers; and storing the target data into the storage space.