To satisfy the requirement of an ultra-micro dispensing volume no more than 1 pL in micro-assembly and sealing engineering, an ultra-micro dispensing method applicable to both contact dispensing and non-contact dispensing was presented. In this method, a needle was moved through the capillary equipped with dispensing fluid and the droplet was adhered to its tip. When the needle tip approached to the target surface, the dispensing could be achieved due to the interfacial tension between the adhered droplet and the target surface. The dispensing volume could be easily controlled by matching the parameters of dispensing process. This method is suitable for any viscosity dispensing fluid ranging from 1 cP to 3.5×105 cP, and can dispense for spatial arbitrary directions. Based on an ultra-micro dispensing experiment platform built in this paper, the influences of needle diameter and gap (the distance between needle tip and target surface) on the size of dispensing spot were investigated. According to the studies, proper needle diameters, gaps, inner diameters of capillary and dispensing velocity were chosen, the ultra-micro dispensing with the volume of 40 fL, 170 fL and 180 fL was achieved when the fluid viscosity was 971 cP and the dispensing spot diameter was 243.9 μm, as well when the viscosity was up to 3×104 cP. The experimental results verify that the proposed method is feasible.