The present invention relates to a method for determining rapidly and accurately the polishing time of a chemical mechanical polishing process for polishing target wafers to avoid any problems of under-polishing or over-polishing. An aspect of the present invention is directed to a method for determining a chemical mechanical polishing time for removing a target polishing thickness H from an uneven surface of a target wafer. The method comprises polishing a control wafer by a chemical mechanical polishing to obtain a progressive relationship of polishing thickness and respective polishing time therefor. A first polishing time T1 is determined for removing a first thickness H1 from the target wafer, in which the first thickness H1 with substantially the uneven surface removed is smaller than the target polishing thickness H of the target wafer to be removed. In some embodiments, the first polishing time T1 is determined by polishing the target wafer to remove the first thickness H1 by chemical mechanical polishing. The method comprises calculating an image polishing thickness H1′ to be removed from the control wafer with respect to the first polishing time T1 according to the progressive relationship of the polishing thickness and respective polishing time for the control wafer. A second polishing thickness H2=(H−H1) is added to the image polishing thickness H1′ to obtain an equivalent polishing thickness H1′ for the control wafer. A target polishing time is determined for removing the target polishing thickness H from the target wafer by interpolating the progressive relationship of the polishing thickness and respective polishing time for the control wafer based on the equivalent polishing thickness H′.