The hyperfine resolved rotational spectrum of the CH2CP radical in the (X) over tilde B-2(1) ground electronic state has been observed for the first time using a Fourier transform microwave spectrometer in combination with a pulsed discharge nozzle. The radical was produced by discharging a mixture of PH3 and C2H2 diluted in either Ar or Ne. A total of 25 hyperfine components of the 2(02)-1(01) and 3(03)-2(02) transitions have been measured which enabled us to precisely determine hyperfine coupling constants for both phosphorus and hydrogen nuclei. Spin densities on the phosphorus and beta-carbon atoms, estimated from the hyperfine coupling constants, suggest that the radical forms an allenic structure (CP double bond) that is modified by a phosphoryl structure (CP triple bond), which is consistent with the theoretical estimation obtained previously by an ab initio calculation. The nature of the CP chemical bond in the radical is investigated in comparison with the corresponding nitrogen bearing counterparts.