A method and apparatus for crosstalk channel estimation based on a measured signal-to-noise (SNR) of a loaded line. The method for channel estimation includes: loading, on a newly added line K, a combination of K-1 signals sent on lines 1 to K-1; obtaining a measured SNR of the line K loaded with the combination of the K-1 signals sent on the lines 1 to K-1; and calculating crosstalk channels of the line K according to K-1 coefficients of the K-1 signals sent on the lines 1 to K-1 and the measured SNR. Embodiments of the present invention may be used for relevant network communications systems such as xDSL systems.