Vertical stratification is one of the basic features of oceans, and almost all marine disciplines require direct or indirect profile information for measurement and analysis. LiDAR is the only remote sensing technology that can be used to obtain the profile information of oceans at a depth of over 100 m, and the echo signals of LiDAR are mainly affected by the joint absorption and scattering effect of water molecules and particulate matter in oceans. When the backscattered signals of LiDAR at 180° are used for the inversion of the components of the particulate matter in oceans, the complexity of water optical properties is determined by the complexity of particulate matter in aspects such as grain size, components, shapes, and internal structure. The particulate matter includes living phytoplankton and their degradation products, inorganic particles (suspended sediment), zooplankton, and air bubbles. The volume scattering coefficient β(π) at 180° is the basic parameter for the water body detection of LiDAR, and the scattering phase functions of different phytoplankton particles differ by a factor of 10 at 180°. In LiDAR simulations and calculations, researchers use the general-purposed volume scattering functions measured by Petzold and the polarization parameter of the Mueller matrix measured by Voss & Fry, which may cause significant divergence compared with specific in-situ results. Given this basic and paramount problem in LiDAR and also in active and passive optical ocean observing and detection, this paper gives a review in this regard. Moreover, the major theoretical and technological problems to be solved are put forward by referring to the relevant research results in recent years.