Taking the Minghuazhen Formation of Neogene in Gangxi Development area of Huanghua depression as an example, the paper is mainly focused on the method of sedimentary microfacies 3D modeling towards the area with a relatively sparse well network using the quantitative geometrical data obtained from the area with a dense well network with the similar sedimentary environment during the oilfield development stage. The result of the study on the area with dense well network shows, the width of the single channel sand body ranges from 50 to 300 meters , generally from 100 to 200 meters, and the thickness ranges from 5 to 15 meters , generally from 6 to 10 meters. The length and width of the overflow sand body are less than 200 meters. Jigsaw—puzzle and labyrinth are the two main sand architecture types. Based on the quantitative geometrical data obtained from the dense well network area, we adopt marked point process  method, carry out 3D sedimentary microfacies modeling study aiming at the target area with a relatively sparse well network, and achieve better effctiveness .