A number of methods based on the deep learning have been applied to medical image segmentation and have achieved state-of-the-art performance. The most famous technique is U-Net which has been used to many medical datasets including the Chest X-ray. Due to the importance of chest x- ray data in studying COVID-19, there is a demand for state-of- art models capable of precisely segmenting chest x-rays. In this paper, we propose a dual encoder fusion U-Net framework for Chest X-rays based on Inception Convolutional Neural Network with dilation, Densely Connected Recurrent Convolutional Neural Network, which is named DEFU-Net. The densely connected recurrent path extends the network deeper for facilitating context feature extraction. In order to increase the width of network and enrich representation of features, the inception blocks with dilation have been used. The inception blocks can capture globally and locally spatial information with various receptive fields to avoid information loss caused by max-pooling. Meanwhile, the features fusion of two path by summation preserve the context and the spatial information for decoding part. We applied this model in Chest X-ray dataset from two different manufacturers (Montgomery and Shenzhen hospital). The DEFU-Net achieves the better performance than basic U-Net, residual U-Net, BCDU- Net, R2U-Net and attention R2U-Net. This model approaches state-of-the-art in this mixed dataset. The open source code for this proposed framework is public available.