In this study, field application test for Suction Drain Method, which can improve the soft ground without surcharge loading or sealing sheet was performed to find out the construction period and improvement degree with suction pressure stage. Also, the analysis program for optimized finite elements with Suction Drain Method was developed, and compare and analyze with analysis results of commercial program and field test construction. As a result, settlement data from existed program was larger than actual field test data. On the contrary, analysis results of Suction-CAIN program were similar to field test results.