A sample-based phone boundary detection algorithm is proposed in this paper. Some sample-based acoustic parameters are first extracted in the proposed method, including six sub-band signal envelopes, sample-based KL distance and spectral entropy. Then, the sample-based KL distance is used for boundary candidates pre-selection. Last, a supervised neural network is employed for final boundary detection. Experimental results using the TIMIT speech corpus showed that EERs of 13.2% and 15.1% were achieved for the training and test data sets, respectively. Moreover, 43.5% and 88.2% of boundaries detected were within 80- and 240-sample error tolerance from manual labeling results at the EER operating point.