A sensing method for detecting a touch condition of a sensing array which comprises a plurality of sensing rows (4-1,...,4-N), comprising: (a) selecting at least one of the sensing rows (4-1,...,4-N) to be detected for a sensing operation; obtaining a sensing curve according to a plurality of sensing data signals extracted from the sensing row (4-1,...,4-N), wherein the sensing row (4-1,...,4-N) comprises a plurality of sensing cells (C-4-1,...,C-4-M), and the plurality of sensing data signals are extracted from the plurality of sensing cells (C-4-1,...,C-4-M) respectively; calculating the difference between every two sensing data signals among the plurality of sensing data signals to obtain a plurality of differential values; and obtaining the sensing curve according to the plurality of differential values; (b) determining whether a profile form of the sensing curve matches with one of a plurality of predetermined profile forms stored in a memory, wherein the profile forms are obtained according to differential values, which are not affected by interference noise, and are represented by a plurality of geometric symbols, each of said geometric symbols being one of one or two regular triangles, one or two inverted regular triangles, a right angled triangle and an inverted right-angled triangle; (c) obtaining a touch condition of the sensing row according to the determination result related to the sensing row; and after determining that the profile form of the sensing curve does not match one of the predetermined profile forms stored in the memory and obtaining a touch condition the sensing operation is ended or the sensing method returns back to the step (a) of selecting at least one of the sensing rows. (a) selecting at least one of the sensing rows (4-1,...,4-N) to be detected for a sensing operation; obtaining a sensing curve according to a plurality of sensing data signals extracted from the sensing row (4-1,...,4-N), wherein the sensing row (4-1,...,4-N) comprises a plurality of sensing cells (C-4-1,...,C-4-M), and the plurality of sensing data signals are extracted from the plurality of sensing cells (C-4-1,...,C-4-M) respectively; calculating the difference between every two sensing data signals among the plurality of sensing data signals to obtain a plurality of differential values; and obtaining the sensing curve according to the plurality of differential values; (b) determining whether a profile form of the sensing curve matches with one of a plurality of predetermined profile forms stored in a memory, wherein the profile forms are obtained according to differential values, which are not affected by interference noise, and are represented by a plurality of geometric symbols, each of said geometric symbols being one of one or two regular triangles, one or two inverted regular triangles, a right angled triangle and an inverted right-angled triangle; (c) obtaining a touch condition of the sensing row according to the determination result related to the sensing row; and after determining that the profile form of the sensing curve does not match one of the predetermined profile forms stored in the memory and obtaining a touch condition the sensing operation is ended or the sensing method returns back to the step (a) of selecting at least one of the sensing rows.