Several structure types of two dimensional position sensitive detectors have been developed,and three type of them are concerned in this paper.They are the tetra lateral PSD,the modified tetra lateral PSD and the resistance bordered PSD .The structure characteristic and operation principle of these three type PSD are described,and their current output formula are derived theoretically.The linearity position grid maps based on the current and the position formula are obtained and compared.The maximum position error in the 60% sensitive area of tetra lateral PSD and modified tetra lateral PSD are 10.0% and 5.0%,respectively.The current position characteristic of the bordered PSD is linear.These theoretical results are agreed with the experimental results.