10％。 Heat transfer and pressure drop performance of 11 kinds of compact smooth fins with different geometry parameters were studied experimentally. Re=600～7000, the influence of the fin pitch, fin height and fin length on heat transfer as well as pressure drop were analyzed .The experimental results showed the fin pitch have small influence on the heat transfer and pressure drop, but fin height and fin length have the evident influence on both. The correlation of j and f were provided on the basis of 220 data with 11 kinds of smooth fins of different geometry parameter compact, the correlation predicts data within error of ±10%, the average deviation of predict data of j and f correlation is 0.2% and 0.1%, mean deviation is 4.2% and 2.1%.