OBJECTIVE： To optimize the ultrasonic extraction technology of total saponins from pine needles of Cedrus deodara （TSPNCD）， and to investigate its in vitro antitumor activity. METHODS： The content of TSPNCD was determined by UV spectrophotometry. Based on single factor test， ethanol volume fraction， solvent-material ratio and extraction time were selected as influential factors during ultrasonic extraction. According to Box-Behnken design， using the content of TSPNCD as response value， response surface analysis was conducted and used to optimize the ultrasonic extraction technology of TSPNCD. The effects of TSPNCD on the proliferation of  human lung cancer A549 cells， human hepatocellular carcinoma HepG2 cells and human gastric cancer MKN45 cells were detected， and IC50 of them were calculated. RESULTS： Optimal technology was that extraction solvent was 73％ ethanol； solvent-material ratio was 13 ∶ 1； ultrasonic extraction times was twice， each time for 65 min. Under the above conditions， the average content of TSPNCD reached 6.693 mg/g， and relative error between it and predicted value （6.508 mg/g） was 2.84％. TSPNCD inhibited the growth of A549 cells， HepG2 cells and MKN45 cells in a dose-dependent manner， with the IC50 values of （63.98±6.79），（154.91±10.20），（176.32±14.26） μg/ml， respectively. CONCLUSIONS： The ultrasonic extraction technology was verified as reasonable and feasible. TSPNCD has certain inhibitory effect on the proliferation of A549 cells， HepG2 cells and MKN45 cells， especially for A549 cells.