Abstract: In order to improve the welfare and health level of laying hens, alternative housing systems for egg production are emerging and increasingly adopted by egg producers.Perching systems are among those worthy of consideration for adoption, since they can increase the laying hens′ vertical and horizontal activity space, and also allow them to express their natural roosting behavior, which is an important indicator of good welfare.Yet along with the shift to the perching systems comes the need to investigate whether the new design of such system, such as the location, number, or size of the perches, can accommodate the laying hens′ behavioral needs when at rest.These needs are often investigated by observing the laying hens′ distribution in the perches.However, such information is seriously lacking or hard to acquire automatically, and the manual collection of the data is not only inefficient, but also disturbs the laying hens even though it′s achievable occasionally.To enable continuous monitoring of perch use, time spent at perches and frequency of visits to perches by laying hens, a system for the automatic monitoring of laying hens′ perch distribution based on LabVIEW platform was developed, and the main features consist of an on site data acquisition module, a system calibration module, a data analysis module, and a remote user interface module.The automated monitoring system employs load cell weighing, video imaging and a data acquisition system.The experiment was carried out in a perch system between August 26, 2015 and September 26, 2015 at the Shang Zhuang Experimental Station of China Agricultural University.The system was equipped by feeders, manure belt, nest boxes, perches, egg belt and etc.The experiment unit housed a breeding group of 80 hens and 8 cockerels, and 15 perches were equipped inside and numbered from 1 to 15.Every weighing node was formed by 2 weight sensors fixed on the cage stents and a two meter long perch.The weight calibration equation was obtained at the beginning of the experiment by least square fitting the collection value and the actual weight value and was applied to the data acquisition program.A synchronous image was captured by a network camera when the distribution weight data were collected.The laying hens′ distribution values on the 6th, 7th and 8th perches for every image were identified manually and then compared with the data calculated by the system to verify the system accuracy.The results showed that the accuracy of the laying hens′ average distribution value was higher than 90%, and when the distribution number was less than 6, the accuracy was greater than 99%.There were about 40 hens on the perches at night during the period of the experiment, which indicated the 50% perch utilization.At the age of 70 weeks, the absolute error of the laying hens′ average weight between measured manually and calculated by the system was within 0.1 kg.Thus, the simplified system can be applied to monitor the average body weights of laying hens during rearing period.The monitoring system can supply the real time information of laying hen perch distribution accurately in the perching systems.This paper describes the detailed design and development of the automated monitoring system of laying hens perch distribution.Such a system can provide data support and reference for perching system design of laying hens.