Vector-space distributed representations of words can capture syntactic and semantic regularities in language and help learning algorithms to achieve better performance in natural language processing tasks by grouping similar words. With progress of machine learning techniques in recent years, much attention has been paid on this field. However, many NLP tasks such as text summary and sentence matching treat sentences as atomic units. In this paper, we introduce a new model called DRWS which can learn distributed representations for words and variable-length sentences. Feature vectors for words and sentences are learned based on their probability of co-occurrence between words and sentences using a neural network. To evaluate feature vector...