We present 12CO (2-1) data for four spiral galaxies (NGC 4330, NGC 4402, NGC 4522, NGC 4569) in the Virgo cluster that are undergoing different ram pressure stages. The goal is to probe the detailed molecular gas properties under strong intra-cluster medium (ICM) pressure using high-resolution millime- ter data taken with the Submillimeter Array (SMA). Combining this with Institut de RadioAstronomie Millimetrique (IRAM) data, we also study spatially resolved temperature and density distributions of the molecular gas. Comparing with multi-wavelength data (optical, Hi, UV , Hα), we discuss how molecular gas properties and star formation activity change when a galaxy experiences Hi stripping. This study suggests that ICM pressure can modify the physical and chemical properties of the molecular gas sig- nificantly even if stripping does not take place. We discuss how this affects the star formation rate and galaxy evolution in the cluster environment.