The figure marks the lowest level since the Bank of Korea (BOK) began compiling related data in 1996.
The deposit rate slightly rose to 2.16 percent in December last year, before sliding in January.
Banks' leading rate was also down by 0.04 percentage point to 3.86 percent in February from a month earlier, the BOK said.
In an unexpected move on March 12, the central bank slashed the base rate by 0.25 percentage point to a record low of 1.75 percent in an effort to bolster growth momentum. Previously, the BOK lowered the benchmark interest rate by 0.25 percentage point each in August and October 2014.